Construction Calculators · 220 Tools
Construction estimates, with the math shown.
Free, instant, US units or metric.
Concrete volumes. Roof shingles. Paint quantities. AC sizing. Every formula is shown, every number is editable, and nothing leaves your browser.
Plan a whole job
Goes further than a single figure — set out a whole floor and see where every cut lands before you order.
- Set-out Tile & Paving Layout Planner See where the cuts land before you order. Compare start positions, work round cut-outs, and export the drawing and cut list.
- Estimate Price it on PlainEstimate Turn a calculator's materials into a priced estimate: press Price it on PlainEstimate under a result and the materials open as a new estimate in PlainEstimate, our free estimate and invoice app. No account needed.
Most-used calculators
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Concrete Slab Calculator
Calculates concrete volume for slabs, patios, sidewalks, and driveways
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Asphalt Shingle Calculator
Calculates asphalt shingles by squares (100 sq ft)
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Paint Calculator
Calculates gallons of paint needed by wall area and coat count
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Brick Calculator
Calculates bricks needed for walls or veneer
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Attic / Loft Insulation Calculator
Calculates rolls of mineral-wool loft insulation
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Kitchen Remodel Cost Calculator
Estimates kitchen remodel cost
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Concrete & Foundations (15)
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View all →From the blog
All posts →-
Timber & Framing How Many Decking Boards Do I Need Rows across the deck, running length along it, whole boards to cover that length. The formula, a worked example carried through in metric with imperial equivalents, the gap and wastage allowances that shift the count, and the board sizes that the same question travels under in the UK, North America and Australia. -
Timber & Framing Board Feet and Timber Volume Explained A board foot is a unit of volume, not of length, and a cubic metre holds 423.8 of them. The formulas both ways, a worked example in metric with imperial equivalents, and the nominal-versus-finished distinction that inflates most timber tallies by about half. -
Roofing Flat Roof Materials: EPDM, GRP and Felt Coverage Flat roof materials are ordered against the covering, not the deck. The formula, a worked example on a 32.4 m² extension roof, and where upstands and laps add a fifth to the order.
Estimates, not advice.
BuildMetricLab is a planning tool. Results are intended to help you scope a job and request quotes — they are not a substitute for a licensed contractor's quote, structural engineer's calculation, or building control or permit sign-off. Always verify with a professional before ordering materials or starting work.