🧱 Concrete Calculator
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🧱 Brick Calculator
Results
🎨 Paint Calculator
Results
🪟 Flooring Calculator
Results
🏠 Roofing Calculator
Results
💰 Material Cost Estimator
Enter unit prices to estimate total material costs based on your calculations above.
| Material | Quantity | Unit | Unit Price ($) | Subtotal ($) |
|---|---|---|---|---|
| Concrete | - | m³ | $0.00 | |
| Bricks | - | pcs | $0.00 | |
| Paint | - | liters | $0.00 | |
| Flooring | - | pcs | $0.00 | |
| Roofing | - | pcs | $0.00 |
Rough material quantities for common building jobs
These five calculators give first-pass quantities for a concrete slab or footing, a single-skin brick wall, painting the walls of a room, tiling or planking a floor, and covering a pitched roof. A sixth tab, the Material Cost Estimator, multiplies those quantities by prices you enter. The results are meant for budgeting and for sanity-checking a supplier’s quote — not for structural design or final ordering.
How to use it
- Open the tab for your job and choose Metric (m) or Imperial (ft). The unit switch applies to the room, wall, slab and roof dimensions; brick sizes and mortar stay in millimetres and tile sizes in centimetres.
- Fill in the dimensions. Optional fields such as mortar thickness, wastage, doors, windows, coats, tile size, tiles per box and pitch angle come with typical defaults you can change.
- Press Calculate. Clear empties the dimension fields, and Copy Results copies the result cards as text.
- After calculating one or more tabs, open Cost Estimator, type a unit price for each material and press Calculate Total Cost.
The assumptions behind each result
Concrete. Volume = length × width × depth (feet are converted with 1 ft = 0.3048 m), also shown in cubic yards. Weight assumes a density of 2,400 kg/m³, and that weight is split 1 : 2 : 3 into cement, sand and gravel as a rough guide — water is ignored and it is not a mix design. The bag count assumes each 40 kg bag of pre-mix yields about 0.012 m³; many products state a higher yield, so check the bag. A 10 m × 5 m slab 0.15 m deep is 7.5 m³ (about 9.81 yd³).
Bricks. Each brick covers its face plus one mortar joint: (length + joint) × (height + joint). With a standard 215 × 65 mm brick and a 10 mm joint that is about 59 bricks per m². The wastage percentage is then added. The page assumes a single-thickness wall and does not subtract openings, and its mortar volume is only a rough figure (wall area × joint thickness × 0.3).
Paint. Wall area = 2 × (length + width) × height, minus 1.9 m² per door and 1.4 m² per window. Paint = area ÷ 10 m² per litre × number of coats, also shown in US gallons. A 5 × 4 m room 2.8 m high with one door, two windows and two coats needs about 9.1 litres. Ceilings are not included.
Flooring. Tiles = floor area ÷ area of one tile, rounded up, then 10% is added for cuts and breakage and the result is divided by tiles per box. A 20 m² floor in 30 × 30 cm tiles needs 223 tiles, 246 with waste, or 23 boxes of 11.
Roofing. The sloped area is the footprint (length × width) divided by the cosine of the pitch angle, and the tile count assumes about 10 tiles per m². A 12 × 6 m footprint at 30° gives about 83 m² and 832 tiles. Overhangs, hips, valleys and ridge pieces are not counted.
Cost. Each subtotal is quantity × your unit price. Quantities are in m³ for concrete, litres for paint and pieces for the rest, even when you entered imperial dimensions, so enter prices per those units. The dollar sign is only a label; any currency works. Nothing you type is saved or sent anywhere — all the arithmetic happens in your browser.
Treat every figure as an estimate. Material yields, local building codes and site conditions vary, so confirm quantities with your supplier or a qualified builder or engineer before you buy materials or start structural work.
Frequently asked questions
How much extra material should I order?
The Bricks tab defaults to 5% wastage and the Flooring tab always adds 10%. Diagonal tile layouts, irregular rooms and fragile materials often need more, and it is common to keep a few spare tiles or bricks for future repairs.
Why is my roof area bigger than the building footprint?
A pitched roof is sloped, so its surface is longer than its horizontal projection. At 30° the surface is about 15% larger than the footprint; at 45° it is about 41% larger.
Can I use it for a flat roof or a wall with windows?
Yes, with care. Enter a pitch of 0 for a flat roof. For a brick wall with openings, subtract the openings yourself by reducing the wall length or height, because the Bricks tab uses the full wall area.
Do I need to calculate every tab before using the Cost Estimator?
No. Rows for materials you have not calculated keep a quantity of zero and add nothing to the total.