Calculator Inputs
Example Data Table
Use these sample inputs to verify your setup and expected output behavior.
| Scenario | Basis | Project requirement | Module size | Efficiency | Waste | Spares | Rounded units |
|---|---|---|---|---|---|---|---|
| Floor panels | Area | 250 m² | 1.2 m × 0.6 m | 95% | 5% | 2 | 387 |
| Interior wall | Wall | 40 m × 3 m − 6 m² | 1.2 m × 0.6 m | 95% | 7% | 3 | 193 |
| Trim run | Linear | 120 m | 1.2 m (per unit) | 98% | 3% | 1 | 107 |
Tip: Your results will differ if you change rounding or pack size.
Formula Used
1) Net project requirement
- Area: NetArea = TotalArea
- Wall: NetArea = (WallLength × WallHeight) − OpeningsArea
- Linear: NetLength = TotalRunLength
- Volume: NetVolume = TotalVolume
2) Nominal module coverage
- Area/Wall: ModuleArea = ModuleLength × ModuleWidth
- Linear: ModuleRun = ModuleLength
- Volume: ModuleVolume = ModuleLength × ModuleWidth × ModuleHeight
3) Efficiency adjustment
EffectiveCoverage = NominalCoverage × (Efficiency ÷ 100)
4) Unit count
TheoreticalUnits = NetRequirement ÷ EffectiveCoverage
AdjustedUnits = TheoreticalUnits × (1 + Waste% ÷ 100) + Spares
5) Rounding and packs
- RoundedUnits applies your chosen rounding rule.
- If PackSize is set, Packs = ceil(RoundedUnits ÷ PackSize).
- If rounding by packs, RoundedUnits = Packs × PackSize.
How to Use This Calculator
- Select the unit system that matches your drawings and BOQ.
- Pick a basis: area, wall, linear run, or volume.
- Enter the project requirement fields for the chosen basis.
- Enter module dimensions, then set efficiency and waste allowance.
- Add spares and pack size if you order in fixed bundles.
- Choose a rounding rule that matches procurement practice.
- Optionally add costs to estimate the total order value.
- Press Calculate, then download CSV or PDF.
Professional Notes on Modular Unit Counting
1) Set the right measurement basis
This calculator supports four common takeoff routes: area for floors and panels, wall for cladding and partitions, linear for trims and service runs, and volume for 3D modular blocks. Select the basis that matches your BOQ item wording. For example, 250 m² of flooring is an area basis, while 40 m × 3 m walls with 6 m² openings are a wall basis.
2) Use module coverage, then apply efficiency
Nominal coverage is calculated from module dimensions (e.g., 1.2 m × 0.6 m = 0.72 m² per unit). Real projects lose coverage to joints, overlaps, tolerances, and cutting lines. The Efficiency input converts nominal coverage into effective coverage. A practical starting range is 90–98% depending on layout complexity and workmanship controls.
3) Include waste and spares for procurement stability
Waste allowance accounts for offcuts, breakage, and rework. Typical values are 3–5% for repetitive layouts and 7–12% for irregular geometry or high defect risk. Spares are counted as whole units and should reflect the client’s maintenance approach. Many teams carry 1–2% spares on critical finishes to avoid future shade variation.
4) Round intelligently with packaging rules
Procurement rarely buys fractions. Rounding up to units protects schedule, while pack rounding protects logistics. If a supplier ships 10 units per pack, rounding to packs prevents leftover partial bundles and reduces handling. For example, an adjusted need of 186.4 units becomes 190 units when rounded up to 19 packs of 10, improving receiving and storage consistency.
5) Add costs for quick budgeting
When you enter cost per unit and labor per unit, the calculator estimates subtotal, tax/VAT, and total order value using the rounded quantity. This is useful for early-stage comparisons between module sizes and installation methods. Always validate final pricing against vendor quotations, freight, and project-specific productivity factors before award.
FAQs
1) What does “efficiency” mean in this calculator?
Efficiency reduces nominal module coverage to reflect joints, overlaps, cutting losses, and workmanship tolerances. If a module covers 0.72 m² nominally, 95% efficiency uses 0.684 m² effective coverage.
2) Should I round to units or to packs?
Round to units when site usage is flexible and procurement allows partial bundles. Round to packs when the supplier ships fixed pack sizes, or when storage and handling efficiency is a priority.
3) How do openings affect wall calculations?
For wall basis, openings area is subtracted from wall length × wall height. This removes doors and windows from the net area before dividing by effective module coverage.
4) What waste percentage should I use?
Use 3–5% for repetitive, straight layouts and good control. Use 7–12% for complex geometry, many penetrations, tight tolerances, or fragile materials. Align with your project’s historical data.
5) Why add spares if I already include waste?
Waste covers installation losses; spares cover future repairs and color-batch matching. Spares are intentional stock, typically kept sealed and documented for maintenance or defect replacement.
6) Can I use this for linear trims and cable trays?
Yes. Choose the linear basis, enter total run length, and set module length as the usable length per unit. Efficiency can account for overlap, joints, and cutting at bends.
7) What currency does the cost output use?
The calculator uses your input values as-is. Enter costs in your preferred currency per unit, add labor and tax if needed, and the total will be in the same currency.