QuantaraMaster BOQ Formulas
BOQ Item Amount
- Qi = measured quantity for item i
- Ri = approved unit rate for item i
- Ai = amount for item i
Total BOQ Cost
Sum of all individual item amounts across the entire project.
Unit-Rate Composition
- M = material cost
- L = labour cost
- E = equipment cost
- OH = overhead allocation
- P = profit or margin allowance
Quantity Measurement Formulas
1. Earthworks and Excavation
Variables
- V = volume in m³
- L = length in m
- W = width in m
- D = depth in m
Example
- L = 20 m
- W = 1.2 m
- D = 2 m
- 20 × 1.2 × 2 = 48 m³
Note: Excavation quantities may also require allowances for working space, side slopes, disposal, backfilling, bulking or compaction, depending on project requirements.
2. Concrete
Example Slab
- L = 12 m
- W = 10 m
- Thickness = 0.15 m
- 12 × 10 × 0.15 = 18 m³
Measure foundations, columns, beams, walls and slabs separately where their dimensions or concrete specifications differ.
3. Masonry and Blockwork
Wall Area
Net Wall Area
Approximate Block Count
Where mortar joints or a manufacturer module affect the effective block area, the estimator must use the approved modular dimensions.
4. Plaster
- measure each applicable face;
- distinguish internal and external finishes;
- apply opening deductions according to the project measurement method;
- include returns, reveals or soffits where required.
5. Painting
For a simple wall:
Coats, primers, surface preparation, texture and substrate type affect the rate, not only the measured area.
6. Floor Tiles
Floor Area
Approximate Tile Count
Waste-Adjusted Quantity
Where w is the approved waste percentage as a decimal.
- 5% waste: w = 0.05
- 10% waste: w = 0.10
7. Ceilings
For a simple horizontal ceiling:
Bulkheads, drops, coffers, access panels, perimeter details and different ceiling systems should be measured separately.
8. Reinforcement Steel
Use the standard estimating approximation:
Unit weight of bar in kg/m
Total bar weight
- D = nominal bar diameter in mm
- L = total bar length in m
- W = approximate weight in kg
Example
- Diameter = 16 mm
- Total length = 20 m
- (16² ÷ 162) × 20 ≈ 31.6 kg
Note: Final reinforcement quantities should account for bar schedules, laps, hooks, bends, couplers, chairs, wastage and approved detailing.
9. Formwork
Basic contact area
Formwork is measured by the concrete-contact surface. Slab soffits, beam sides, beam soffits, column faces, wall faces and foundation sides should be measured according to the applicable project rules.
10. Roofing
Plan-area approximation
These are geometric approximations. Use actual sloped dimensions or approved drawings where available, and measure hips, valleys, ridges, laps and accessories separately.
Illustrative Pitch Factors
| Flat | 1.00 |
|---|---|
| 15° | approx. 1.04 |
| 30° | approx. 1.15 |
| 45° | approx. 1.41 |
11. Asphalt
Volume
Mass
- T = compacted thickness in m
- ρ = approved mix density in t/m³
A density such as 2.35 t/m³ is illustrative only. Use the approved asphalt mix density or supplier data for the project.
12. Pipes
Basic pipe quantity
Accessories should be counted separately where required:
- elbows
- tees
- valves
- reducers
- flanges
- supports
- fittings
- insulation
- testing and commissioning items
Do not imply that the pipe length automatically includes fittings.
13. Structural Steel
- L = member length
- wu = unit weight from an approved steel-section table
- W = total member weight
Plates, bolts, welds, connections, stiffeners, coatings, fabrication loss and erection requirements may need separate measurement or rate allowances.
14. HVAC Ductwork
Duct surface area
- P = duct perimeter in m
- L = duct length in m
- A = duct surface area in m²
Measured per duct section from the verified perimeter and length. Insulation, dampers, flanges, supports and fittings should be measured or counted separately where the project requires it.
15. Electrical Cabling
Cable length
- R = verified route length in m
- V = vertical drops in m (where applicable)
- T = approved termination allowance in m
Containment, first-fix accessories, glanding, and testing and commissioning items should be counted separately; cable length does not automatically include them.
Cost Formulas
Material Cost
- QM = material quantity
- PM = material unit price
Labour Cost
- HL = labour hours
- RL = labour hourly rate
Equipment Cost
- HE = equipment hours
- RE = rental/operating rate
Final Item Cost
Project Total
Worked BOQ Example
| Item | Quantity | Unit | Illustrative Rate | Amount |
|---|---|---|---|---|
| Excavation | 48 | m³ | AED 20 | AED 960 |
| Concrete | 18 | m³ | AED 140 | AED 2,520 |
| Reinforcement | 3,200 | kg | AED 1.50 | AED 4,800 |
| Blockwork | 240 | m² | AED 35 | AED 8,400 |
| Total: | AED 16,680 | |||
Illustrative rates only. These values are not current UAE market rates, quotations or pricing recommendations.
Professional Measurement Workflow
- Review the project drawings, specifications, schedules and revisions.
- Identify the relevant construction elements and measurement units.
- Apply the correct length, area, volume, weight or count method.
- Record assumptions, deductions, waste and source references.
- Apply approved unit rates that reflect the agreed cost components.
- Review every quantity and rate professionally.
- Sum the item amounts to produce the BOQ total.
- Preserve revision identifiers and available source references.
Use the Free BOQ Calculator
Apply practical quantity and cost formulas using the free BOQ Calculator developed by Vista By Lara. The calculator is an external educational planning tool and does not replace professional measurement, rate validation or contractual review.
Frequently Asked Questions
Is there one formula for calculating a BOQ?
No. A BOQ combines different measurement methods. Each construction element is measured using an appropriate length, area, volume, weight or count formula, then multiplied by its reviewed unit rate.
What is the basic BOQ cost formula?
The basic item formula is Quantity × Unit Rate. The BOQ total is the sum of all item amounts.
Does a BOQ calculator replace a quantity surveyor?
No. A calculator can assist with arithmetic and planning, but drawings, dimensions, measurement rules, rates, specifications, assumptions and contractual requirements must be reviewed by qualified professionals.
Can I use the Vista By Lara calculator for UAE projects?
The external calculator can support preliminary quantity and cost planning. Users must replace illustrative values with project-specific dimensions and approved rates and complete professional review.
Does the calculator send results into Quantara?
No automatic transfer is represented. The Vista By Lara BOQ Calculator is a separate educational planning tool.