Practical examples
For now this page contains only worked calculation examples: they show how a calculator is used on a typical task, but they are not measurements from a real site. Documented examples from real jobs will be added when they are available.
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Worked calculation examples
Each example shows the inputs, assumptions and the calculation as the calculator produces it. The examples contain no real consumption, which may differ from the calculation.
Floor tiles for a room with packaging from the label
Illustrative calculation example — not a documented job from a construction site.
Rectangular room, straight laying. The pack size in this example is a value the user would copy from the box, not an assumption of the calculator.
- There are no openings or built-in elements on the floor.
- Reserve for simple laying, as set in the calculator.
- Offcuts from cut tiles are not counted in the purchase.
| Item | Value |
|---|---|
| Inputs | |
| Floor (length × width) | 4.20 m × 3.50 m |
| Tile size | 60 × 60 cm |
| Joint width | 2 mm |
| Reserve (simple laying) | +5 % |
| Pack size (from the box) | 1.44 m² |
| Procedure | |
| Area | 4.20 × 3.50 = 14.70 m² |
| Area including reserve | 14.70 m² × 1.05 = 15.44 m² |
| Number of tiles | 15.44 / 0.36 → 43 pcs |
| Boxes | 15.44 / 1.44 → 11 × 1.44 m² = 15.84 m² (44 pcs) |
| Result before reserve and rounding | |
| Area | 14.70 m² |
| Final result (to buy) | |
| Tiles (boxes) | 11 × 1.44 m² = 15.84 m² (44 pcs) |
| Adhesive (bags) | 93 kg → 4 × 25 kg |
| Grout (packs) | 2 kg → 1 × 5 kg |
The link opens the calculator with this example's inputs filled in; you can change them.
Enter manually: Pack size (from the box).
Skim coat and paint for a room with a window and a door
Illustrative calculation example — not a documented job from a construction site.
Walls and ceiling of one room; the window and door area is deducted from the walls.
- Walls and ceiling get the same number of coats.
- Windows and doors are entered as their total opening area.
- The calculator adds no reserve; surplus comes only from rounding to packs.
| Item | Value |
|---|---|
| Inputs | |
| Room | 4.00 × 3.00 m, h = 2.60 m |
| Windows (total) | 1.50 m² |
| Doors (total) | 1.60 m² |
| Skim coat rate (two coats) | 1.5 kg/m² |
| Paint rate (per coat × coats) | 0.125 L/m² × 2 |
| Procedure | |
| Walls | 2 × (4.00 + 3.00) × 2.60 − 1.50 − 1.60 = 33.30 m² |
| Ceiling | 4.00 × 3.00 = 12.00 m² |
| Skim coat | 45.30 m² × 1.5 kg/m² = 67.95 kg → 68 kg |
| Paint | 45.30 m² × 0.125 L/m² × 2 = 11.33 L → 12 L |
| Result before reserve and rounding | |
| Total area | 45.30 m² |
| Skim coat | 67.95 kg |
| Paint | 11.33 L |
| Final result (to buy) | |
| Skim coat (bags) | 3 × 25 kg = 75 kg |
| Paint (buckets) | 1 × 15 L = 15 L |
The link opens the calculator with this example's inputs filled in; you can change them.
Concrete slab with a stair opening
Illustrative calculation example — not a documented job from a construction site.
One slab with one rectangular opening; volume to order with reserve and rounding.
- The opening is deducted through the full slab thickness.
- The reserve covers losses during placing, not changes in dimensions.
- Mass is an estimate based on the density of fresh concrete.
| Item | Value |
|---|---|
| Inputs | |
| Slab | 6.00 × 4.00 m, d = 0.15 m |
| Slab opening | 1.00 × 2.50 m |
| Reserve | 5 % |
| Volume rounding | 0.1 m³ |
| Procedure | |
| Volume without opening | 6.00 × 4.00 × 0.15 = 3.600 m³ |
| Opening volume | 1.00 × 2.50 × 0.15 = 0.375 m³ |
| Volume | 3.600 − 0.375 = 3.225 m³ |
| Volume including reserve | 3.225 × 1.05 = 3.386 m³ |
| Rounding up | 3.386 → 3.4 m³ |
| Result before reserve and rounding | |
| Volume | 3.225 m³ |
| Final result (to buy) | |
| Volume to order | 3.4 m³ |
| Mass | ≈ 8127 kg |
The link opens the calculator with this example's inputs filled in; you can change them.
Documented examples from real jobs
There are no published documented examples yet. Each future example will state the data source and date, the quantity bought and the quantity used separately, the measured leftover and waste, and an explanation of any deviation.