Construction Estimates and Quantity Surveying - Cheat Sheet
Your last-minute revision companion for rapid recall of formulas, definitions, and exam-critical facts on construction cost estimation and material quantity take-off. Master the 10 must-remember items and key formulas in under 30 minutes.
Quantity Take-Off: Concrete
Formulas
V = L × W × H (or section area × length)
Meaning
V = volume (m³); L, W, H = length, width, height (m); for rectangular sections multiply area by length
Watch out
Don't forget to convert depth/thickness to meters. Mixing cm and m will be off by a factor of 100.
When to use
Every concrete member: footings, slabs, beams, columns, walls. Start here for any concrete estimate.
Cement bags (Class A) = 9 × V (bags/m³)
Meaning
Class A 1:2:4 mix ≈ 9 bags cement per m³ of concrete
Watch out
Class A = 9 bags/m³; Class B (1:2.5:5) = 7.5 bags/m³; Class C = 6.5 bags/m³. DO NOT interchange.
When to use
When concrete class is specified as Class A (1:2:4) and cement quantity is needed
Cement (Class B) = 7.5 × V (bags/m³)
Meaning
Class B 1:2.5:5 mix ≈ 7.5 bags cement per m³
Watch out
Lower strength than Class A; used for non-critical members. Verify mix design from specifications.
When to use
When concrete class is Class B (1:2.5:5)
Sand + Gravel from mix ratio
Meaning
For Class A (1:2:4): 1 part cement + 2 parts sand + 4 parts gravel per m³; scales proportionally with volume
Watch out
1:2:4 ratio is by volume/mass in loose state. Compacted concrete volume ≠ sum of loose components (accounts for consolidation).
When to use
Estimating fine and coarse aggregates when exact volumes are required
Common values
Value
9 bags
Symbol
n_A
Quantity
Cement per m³ — Class A (1:2:4)
Value
7.5 bags
Symbol
n_B
Quantity
Cement per m³ — Class B (1:2.5:5)
Value
6.5 bags
Symbol
n_C
Quantity
Cement per m³ — Class C (1:3:6)
Value
50 kg
Symbol
m_bag
Quantity
Standard cement bag weight
Value
2400 kg/m³
Symbol
ρ_concrete
Quantity
Concrete density
Important facts
- One bag of cement = 50 kg (standard in Philippines)
- Class A (1:2:4) = 9 bags cement/m³; Class B (1:2.5:5) = 7.5 bags cement/m³; Class C (1:3:6) = 6.5 bags cement/m³
- For rectangular concrete members: Volume = length × width × thickness (all in meters)
- ACI 318 and NSCP 2015 are the design standards; QTO is independent of design code but must be from final approved drawings
- Always add 3–5% wastage factor to concrete quantities in the final estimate
- Cement content directly affects cost and strength; verify mix class from specifications
- Concrete density ≈ 2400 kg/m³ (used for weight calculations if needed)
Key definitions
Quantity Take-Off (QTO)
Example
Reading a floor plan and computing total concrete volume in cubic meters.
Process of measuring and calculating quantities of all materials from construction drawings; foundation of the estimate.
Class A Concrete
Example
Used in footings, columns, and beams (ACI 318 reference).
Mix proportion 1:2:4 (cement:sand:gravel) by volume, yielding ~9 bags cement/m³; high-strength for critical members.
Class B Concrete
Example
Used in slabs and non-load-bearing walls.
Mix proportion 1:2.5:5 (cement:sand:gravel) by volume, yielding ~7.5 bags cement/m³; moderate strength.
Diagrams to know
- Simple rectangular footing with dimensions labeled (for volume calculation)
- Typical slab section showing thickness dimension
- Cross-section of beam or column with length and cross-section area marked
Quantity Take-Off: Reinforcing Steel
Formulas
Unit mass of round bar = 0.006165 × d² (kg/m)
Meaning
d = bar diameter in mm; result is mass per linear meter of bar
Watch out
This formula ONLY works when d is in millimeters. If given diameter in cm, convert to mm first. Result is kg/m, not total mass.
When to use
Calculating mass of reinforcing bars for any member (beams, columns, footings); this is the PRIMARY formula for steel estimation.
Total steel mass = unit mass × total length × number of bars
Meaning
Sum the contributions from each bar size and count (e.g., 4 bars × 6 m × 3.85 kg/m)
Watch out
Easy to miss bars if you don't carefully count stirrups, ties, and main bars separately. Each diameter may have a different unit mass.
When to use
After computing unit mass; multiply by bar count and total length in meters
d² (bar diameter squared, mm²) — intermediate step
Meaning
Required input for the unit mass formula; d is always in millimeters
Watch out
Common error: forgetting to square the diameter, or squaring a value in cm instead of mm.
When to use
Before applying 0.006165 × d²
Common values
Value
0.616 kg/m
Symbol
m_10
Quantity
10 mm bar unit mass
Value
0.888 kg/m
Symbol
m_12
Quantity
12 mm bar unit mass
Value
1.578 kg/m
Symbol
m_16
Quantity
16 mm bar unit mass
Value
2.466 kg/m
Symbol
m_20
Quantity
20 mm bar unit mass
Value
3.853 kg/m
Symbol
m_25
Quantity
25 mm bar unit mass
Value
4.834 kg/m
Symbol
m_28
Quantity
28 mm bar unit mass
Value
6.313 kg/m
Symbol
m_32
Quantity
32 mm bar unit mass
Important facts
- Formula 0.006165d² applies ONLY to round bars; d must be in millimeters
- Common bar sizes in Philippines: 10 mm (0.57 kg/m), 12 mm (0.82 kg/m), 16 mm (1.46 kg/m), 20 mm (2.27 kg/m), 25 mm (3.55 kg/m), 28 mm (4.41 kg/m), 32 mm (6.31 kg/m)
- Stirrups and ties are counted separately but use the same formula (0.006165d²) for mass calculation
- Steel drawings show bar count, diameter, length, and spacing; sum all bars of same size to get total length
- Add 2–3% waste factor to estimated steel for cutting and handling losses
- ASTM A615 Grade 40 (fy = 276 MPa) or Grade 60 (fy = 415 MPa) are typical; NSCP 2015 Section 9.2 specifies design strength reduction factors
- Weight per meter tables are usually provided on plans; always verify against the 0.006165d² formula if not given
Key definitions
Reinforcing Steel (Rebar)
Example
10 mm, 12 mm, 16 mm, 20 mm, 25 mm, 28 mm, 32 mm bars are common Philippines sizes.
High-strength steel bars (typically ASTM Grade 40 or 60) embedded in concrete to resist tension; sized by diameter in mm.
Unit Mass
Example
A 25 mm bar has unit mass = 0.006165 × 25² ≈ 3.85 kg/m.
Mass per unit length (kg/m) of a bar, calculated as 0.006165d² for round bars.
Bar Mark
Example
Quantity surveyor lists Bar A, Bar B, Bar C with their sizes and total lengths.
Label on shop drawings identifying each unique bar type (e.g., 'Bar A = 4–25 mm × 6.0 m') for ordering and placement.
Diagrams to know
- Beam reinforcement layout showing main bars, stirrups, and spacing
- Column reinforcement cage diagram with vertical and spiral/tie bars
- Footing rebar layout (plan and section view)
- Slab reinforcement grid with bar spacing and diameter labeled
Quantity Take-Off: Formwork
Formulas
Formwork area = contact area of concrete surface
Meaning
All surfaces of concrete that must be formed/supported during casting; measured in m²
Watch out
Formwork is AREA (m²), NOT volume. Count each exposed face separately (e.g., a beam soffit + two sides ≠ bottom alone).
When to use
Estimating plywood, lumber, and labor for temporary support structures
Beam formwork = (perimeter − bottom) × length
Meaning
For a rectangular beam: typically three sides (soffit + two webs) are formed; bottom may rest on support
Watch out
Check if bottom is formed or bears on existing structure. Verify from drawings which surfaces need formwork.
When to use
Quick calculation for a single rectangular beam
Column formwork = perimeter × height
Meaning
All four sides of a rectangular column form a vertical surface
Watch out
Height of formwork = distance from base to top of concrete pour, not total floor height. Some formwork may be reused between stories.
When to use
Estimating formwork for standing/vertical members
Slab formwork ≈ plan area (for horizontal slabs)
Meaning
Area of plywood or shoring beneath slab = plan dimensions × quantity
Watch out
Do not count slab edges as significant unless they are cantilevered or require vertical forms. Verify from design.
When to use
Flat horizontal slabs; soffit area is the primary formwork area
Common values
Value
18 mm
Symbol
t_ply
Quantity
Plywood thickness (standard)
Value
1.22 m × 2.44 m
Symbol
A_sheet
Quantity
Plywood sheet size
Value
2.98 m²
Symbol
A_sheet
Quantity
Plywood sheet area
Value
1–2 kg/m² of concrete
Symbol
w_bracing
Quantity
Typical formwork bracing rate
Important facts
- Formwork is measured in square meters (m²), not cubic meters (m³)
- Every surface that contacts concrete during pouring must be measured and budgeted
- Common formwork materials: 18 mm plywood (≈₱600–₱800/sheet), 2×2 and 2×4 lumber (bracing), steel props
- Form removal timing varies: slabs and beams typically 14–21 days (depending on strength gain and ambient temperature)
- Formwork cost is often 20–40% of concrete subcontract; poor estimation leads to significant overruns
- Reusable formwork systems (steel frames, modular units) reduce per-use cost but require higher upfront investment
- Safety bracing and props are essential; do not omit from quantity or cost estimate
- NSCP 2015 Section 10.5 requires formwork capable of supporting loads during construction
Key definitions
Formwork (Shuttering)
Example
Wooden forms supporting a reinforced concrete beam during concrete pour.
Temporary mold/support structure (plywood, lumber, steel bracing) that holds concrete in shape during casting and curing.
Contact Area
Example
A 0.3 m × 0.5 m beam, 6 m long: soffit (0.3 × 6) + two webs (0.5 × 6 each) = 0.3(6) + 2(0.5)(6) = 7.8 m².
Total area of concrete surface in direct contact with the formwork; measured in m².
Shuttering Rate
Example
₱150/m² for plywood beam formwork (material + labor + bracing).
Cost per m² of formwork; includes material, labor, and overhead for form construction and removal.
Diagrams to know
- Rectangular beam section showing soffit and web surfaces to be formed
- Column formwork arrangement with props and bracing
- Slab formwork plan view with beam locations and props
- Cross-section of formwork system showing plywood, lumber, and support structure
Direct Cost and Bid Pricing
Formulas
Direct Cost = Materials + Labor + Equipment
Meaning
Sum of all direct, project-specific costs required to produce the work
Watch out
Do NOT include overhead, contingency, profit, or taxes in direct cost. Keep these separate for markup calculation.
When to use
Starting point for every estimate; base for calculating bid price
Bid Price = Direct Cost × (1 + markup)
Meaning
Markup as a decimal (e.g., 0.25 for 25%); includes overhead/contingency/miscellaneous (OCM) and profit
Watch out
Markup base is ALWAYS direct cost. If markup = 25%, then Bid = DC × 1.25, NOT DC + 0.25. Common error: adding markup as if it's additive.
When to use
Final step to convert direct cost to selling/bid price for client
Markup (as percentage) = (OCM + Profit) / Direct Cost × 100%
Meaning
OCM = overhead, contingency, miscellaneous; Profit = net gain
Watch out
OCM is typically 10–15%; profit target is usually 5–15%. Combined = 15–25% is common. Verify with company policy.
When to use
When you need to back-calculate markup from target profit or when comparing bid margins
Bid with VAT = Bid Price × (1 + 0.12)
Meaning
VAT (Value Added Tax in Philippines) = 12% of selling price (when applicable)
Watch out
VAT is typically added AFTER the bid price. Some contracts are VAT-inclusive, others exclusive. Clarify in the contract.
When to use
When estimating must include Philippine tax burden (RA 8293, Tax Code)
Common values
Value
10–15% of DC
Symbol
OCM%
Quantity
Typical OCM (overhead/contingency/misc)
Value
5–15% of DC
Symbol
Profit%
Quantity
Typical profit margin
Value
15–25% of DC
Symbol
Markup%
Quantity
Combined typical markup
Value
12%
Symbol
VAT
Quantity
Philippine VAT
Value
1.25
Symbol
λ
Quantity
Markup multiplier (25%)
Important facts
- Direct cost = materials + labor + equipment ONLY; no overhead or profit
- Markup formula: Bid = DC(1 + m), where m is markup as decimal (0.25 for 25%), NOT DC + markup amount
- Typical markup breakdown: OCM 10–15% + profit 5–15% = total 15–25%
- VAT in Philippines = 12%, applied to final bid price (unless contract specifies otherwise)
- RA 544 (Civil Engineer Licensure Law) requires licensed engineers to sign cost estimates; RA 8293 governs intellectual property and related taxes
- Material price fluctuations (cement, steel, lumber) significantly impact estimates; include price escalation clauses in long-duration projects
- Labor rates vary by region and skill level (skilled, semi-skilled, unskilled); use market rates current to bid date
- Equipment rental/amortization must account for depreciation and maintenance; spread over project duration
Key definitions
Direct Cost
Example
₱500,000 for concrete + ₱150,000 for labor = ₱650,000 direct cost (before markup).
Sum of labor, materials, and equipment costs directly attributable to construction; does not include indirect costs or profit.
Overhead & Contingency (OCM)
Example
Project manager salary, site office rent, contingency reserve.
Site supervision, small tools, insurance, contingency for unknowns, and miscellaneous project expenses; typically 10–15% of direct cost.
Bid Price (or Contract Price)
Example
Direct cost ₱650,000 + markup 25% = bid ₱812,500.
Final selling price quoted to client after adding markup for OCM and profit; may be adjusted for VAT.
Markup
Example
25% markup on ₱500,000 DC = ₱125,000 markup; bid = ₱625,000.
Percentage (or ratio) applied to direct cost to cover indirect costs and profit; typical range 15–25%.
Diagrams to know
- Cost breakdown diagram: Direct Cost → OCM → Profit → Bid Price
- Bid calculation flowchart: Quantities → Unit Costs → Direct Cost → Markup → Bid
- Cost component pie chart showing typical % split (materials, labor, equipment, OCM, profit)
Unit Costs and Material Pricing
Formulas
Unit Cost = Total Cost / Quantity
Meaning
Cost per unit (e.g., ₱/m³ concrete, ₱/kg steel, ₱/m² formwork)
Watch out
Always specify the unit clearly (m³, kg, m², piece, hour). Mixing units leads to errors of orders of magnitude.
When to use
Converting material/labor/equipment expenses into rates for easy multiplication by total quantity
Total Material Cost = Unit Cost × Quantity
Meaning
Quantity from take-off × unit cost from market = line-item cost
Watch out
Verify that quantity unit matches the unit cost unit. If QTO is in m³ but price is per bag of cement, conversion is required.
When to use
For every material: concrete (m³ × ₱/m³), steel (kg × ₱/kg), formwork (m² × ₱/m²), labor (hours × ₱/hour)
Labor Cost = Labor Rate (₱/hour or ₱/day) × Hours or Days
Meaning
Wage cost for direct labor to place/finish materials
Watch out
Labor rates include basic wage, SSS, PhilHealth, and other statutory contributions. Do NOT forget to include mandatory benefits.
When to use
Estimating labor component of direct cost; varies by skill level and region
Common values
Value
₱3,000–₱4,000/m³
Symbol
UC_conc
Quantity
Typical concrete ready-mix (PMC)
Value
₱200–₱300/bag
Symbol
UC_cem
Quantity
Typical cement (bag, 50 kg)
Value
₱25–₱40/kg
Symbol
UC_steel
Quantity
Typical rebar (10–32 mm)
Value
₱600–₱900/sheet
Symbol
UC_plywood
Quantity
Typical plywood (18 mm)
Value
₱400–₱600/day
Symbol
UC_labor_skilled
Quantity
Skilled carpenter daily rate
Value
₱250–₱400/day
Symbol
UC_labor_unskilled
Quantity
Laborer daily rate
Important facts
- Material costs are obtained from supplier quotations; always solicit 3+ bids for comparison
- Labor rates vary by region, skill level, and market conditions; use project-relevant prevailing rates
- Concrete unit cost typically includes delivery; verify whether batching plant quotation is free-on-site or f.o.b. plant
- Steel prices are volatile; include price escalation clauses for projects > 3 months duration
- Formwork cost varies based on reusability, site conditions, and form system (timber, steel, proprietary); obtain quotes from formwork contractors
- Equipment rental rates include operator, fuel, maintenance; get quotations from equipment rental companies
- Currency fluctuations (if materials are imported) may affect pricing; lock in rates or include hedging costs
- Quantity discounts apply for bulk material orders; negotiate volume rates with suppliers
Key definitions
Unit Cost
Example
Concrete ready-mix from batching plant: ₱3,500/m³ (delivered to site).
Price per unit measure (₱/m³, ₱/kg, ₱/m², etc.) from supplier quotation or market survey.
Material Supply Rate
Example
Cement: ₱250/bag; 25 mm rebar: ₱35/kg.
Wholesale or retail cost of material; obtained from supplier quotes or market databases.
Labor Rate
Example
Skilled carpenter: ₱350–₱500/day; laborer: ₱250–₱350/day (varies by region and project).
Hourly or daily wage for skilled, semi-skilled, or unskilled worker; includes statutory contributions.
Diagrams to know
- Cost breakdown for concrete: unit cost breakdown (cement, sand, gravel, delivery, batching labor)
- Labor cost structure: hourly rate + statutory contributions (SSS, PhilHealth, PAGIBIG, income tax)
- Material price comparison table (3 supplier bids side-by-side)
Take-Off Organization and Common Pitfalls
Important facts
- Always cross-check quantities from multiple drawings (plan, elevation, section) to catch discrepancies
- Organize QTO by work section (concrete, steel, formwork, etc.) for clarity and to prevent omissions
- Use a standard BOQ template; include columns for quantity, unit, unit cost, and total cost
- Double-check all dimensions: convert cm to m before calculating volume/area
- Mark off completed items on drawings as you take-off to avoid double-counting or omissions
- Sum all items by work type before finalizing; verify total concrete volume, total steel mass, total formwork area separately
- Add 3–5% wastage to concrete; 2–3% to steel; proportionally to formwork based on reusability
- Document all assumptions (mix class, labor rates, schedule, material source) in the estimate memo
- Obtain cost data current to the bid date; material prices are volatile and region-dependent
Key definitions
Bill of Quantities (BOQ)
Example
Section 1: Concrete (footing, slab, column); Section 2: Reinforcing Steel; Section 3: Formwork; Section 4: Finish.
Standardized list of all measured items from the take-off, organized by work type; serves as basis for bidding and contract administration.
Wastage Factor
Example
Concrete estimate + 5% waste = 1.05 × volume; steel + 3% waste = 1.03 × mass.
Percentage added to QTO to account for cutting losses, spillage, and handling damage (typically 3–5%).
Contingency
Example
Direct cost ₱500,000 + 7% contingency = ₱535,000.
Reserve fund (usually 5–10% of direct cost) for unforeseen costs and design changes during construction.
Diagrams to know
- Sample BOQ template structure: Work Item | Quantity | Unit | Unit Cost | Total Cost
- Take-off checklist flowchart: Read drawings → Verify dimensions → Calculate volume/area → Add waste → Sum by type → Cross-check
Exam Formula Reference — Quick Lookup
Formulas
Concrete volume: V = L × W × H (m³)
Meaning
Rectangle: length × width × height; for slabs/footings/blocks
Watch out
All dimensions in meters; do NOT mix cm and m.
When to use
First step in any concrete take-off
Cement (Class A): n_A = 9 × V (bags)
Meaning
9 bags per m³ for 1:2:4 mix
Watch out
Class B = 7.5 bags/m³; Class C = 6.5 bags/m³. Memorize all three.
When to use
When Class A is specified
Steel unit mass: m = 0.006165 × d² (kg/m)
Meaning
d in mm; result in kg/m
Watch out
d MUST be in millimeters. If given in cm, multiply by 10 first. Common error: using area instead of this formula.
When to use
For every bar type; then multiply by total length and bar count
Bid price: B = DC × (1 + m)
Meaning
DC = direct cost; m = markup (decimal, e.g., 0.25 for 25%)
Watch out
Multiply, do NOT add. B = DC × 1.25, NOT DC + 0.25.
When to use
Final step from direct cost to bid price
Important facts
- The four core formulas: V = LWH (concrete); n = 9V (cement Class A); m = 0.006165d² (steel); B = DC(1+m) (bid)
- For any concrete member: measure from drawings, compute volume, apply cement factor, done
- For any bar: look up or compute unit mass 0.006165d², multiply by total length, done
- For bid: sum all direct costs, multiply by (1 + markup), done
Must remember
- Concrete volume: V = L × W × H (meters). Class A 1:2:4 = 9 bags cement/m³. Always verify mix class from specs.
- Steel unit mass: m = 0.006165d² kg/m (d in millimeters). Memorize the coefficient 0.006165 and the formula structure.
- Total steel mass: unit mass × total length × bar count. Count stirrups/ties separately from main bars.
- Bid formula: Bid = Direct Cost × (1 + markup), NOT direct cost + markup amount. Common multiplier for 25% markup is 1.25.
- Formwork is measured in m² (area), never m³ (volume). Include all surfaces in contact with concrete.
- Material unit costs vary by region and date; always obtain current quotations. Concrete, steel, and timber are volatile.
- Direct cost = materials + labor + equipment ONLY. Overhead, contingency, and profit are added via markup.
- Add wastage factors: concrete 3–5%, steel 2–3%, formwork per reuse plan. Document all assumptions in estimate memo.
- Cement: Class A = 9 bags/m³, Class B = 7.5 bags/m³, Class C = 6.5 bags/m³. Do not interchange.
- For exam problems: always show units, verify dimension consistency (no cm-meter mix), and cross-check final answer with reasonableness test.
Last minute tips
- If the problem gives diameter in cm (e.g., 2.5 cm bar), convert to mm (25 mm) BEFORE applying the steel formula 0.006165d². This is the #1 steel calculation error.
- When calculating concrete cement, ALWAYS confirm the mix class (A, B, or C) from the problem or specifications. Defaulting to Class A will mark you wrong if Class B or C is intended.
- Bid price formula: B = DC(1 + m). If you write B = DC + m, you will lose marks. The markup multiplies the DC, it doesn't add linearly.
- Formwork is area (m²). If you calculate it as volume (m³), the answer will be off by orders of magnitude. Visualize the surfaces being formed.
- In the last 5 minutes before exam, write down the four key formulas on your scratch paper: V = LWH, cement = 9V, m = 0.006165d², B = DC(1+m). Use them as a safety checklist.
Comparison tables
Concrete Mix Classes (Philippines)
| Class | Proportion (C:S:G) | Cement bags/m³ | Typical use | Strength approx. |
|---|---|---|---|---|
| Class A | 1:2:4 | 9 bags | Footings, columns, beams, high-strength members | ~24 MPa @ 28d |
| Class B | 1:2.5:5 | 7.5 bags | Slabs, moderate-load members | ~20 MPa @ 28d |
| Class C | 1:3:6 | 6.5 bags | Non-load-bearing walls, filler | ~17 MPa @ 28d |
Steel Unit Mass (by diameter)
| Diameter (mm) | Unit mass (kg/m) | Common use |
|---|---|---|
| 10 | 0.616 | Ties, spirals |
| 12 | 0.888 | Light reinforcement, ties |
| 16 | 1.578 | Slab bars, light beams |
| 20 | 2.466 | Beam and column bars (common) |
| 25 | 3.853 | Beam and column bars (common) |
| 28 | 4.834 | Heavy columns, large beams |
| 32 | 6.313 | Heavy columns, large beams |
Direct Cost vs. Bid Price (example 25% markup)
| Item | Direct Cost | Markup calculation | Bid Price |
|---|---|---|---|
| Concrete | ₱500,000 | 500k × 1.25 | ₱625,000 |
| Reinforcing steel | ₱150,000 | 150k × 1.25 | ₱187,500 |
| Formwork | ₱200,000 | 200k × 1.25 | ₱250,000 |
| Total | ₱850,000 | 850k × 1.25 | ₱1,062,500 |
Take-Off Checklist by Work Type
| Work type | Measurement unit | Key formula/method | Common mistakes |
|---|---|---|---|
| Concrete | m³ | V = L × W × H; cement = 9V (Class A) | Wrong mix class; forgetting decimal placement |
| Reinforcing steel | kg | m = 0.006165d² × length × count | Diameter in cm not mm; forgetting stirrups |
| Formwork | m² | Contact area (soffit + sides) | Treating area as volume; missing vertical faces |
| Labor | hours or days | Hours × hourly rate or days × daily rate | Omitting statutory contributions (SSS, PhilHealth) |
Diagrams
Construction Estimates: Key Formula Map
Mind map showing the hierarchy of all major formulas and concepts in construction estimating. Concrete volume and cement content at the top; steel mass calculation; formwork area; direct cost components; and the final bid price formula at the bottom.
Quantity Take-Off and Bid Calculation Process
Flowchart showing the complete process from reading drawings through calculating volume/area/mass, obtaining unit costs, computing direct cost, applying markup, and arriving at the final bid price. Each decision point (concrete, steel, formwork) branches to the appropriate calculation method.
Cost Estimation State Progression
State diagram showing the progression from quantity take-off through direct cost calculation to final bid price. Each state represents a major phase; transitions show the logical flow and requirements for advancing to the next phase.