Loona Construction Calculators

Free Construction Calculators

Paint, tile, concrete, brick, roofing, stairs and more — every calculator works in metric and imperial units, includes a waste allowance, and shows its formula with a worked example. Built for DIYers, tradespeople and renovators across Europe and the world.

100% FreeNo Sign-upMetric + ImperialRuns in Your Browser

All 12 Construction Calculators

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Paint Calculator

Litres & gallons for any room, doors/windows subtracted, primer included.

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Tile Calculator

Tiles and boxes for floors & walls, grout gap counted.

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Concrete Calculator

Slab volume in m³ & yd³ plus pre-mix bag count.

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Flooring Calculator

Laminate, vinyl & wood boxes with cutting waste.

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Drywall Calculator

Plasterboard / drywall sheets for walls & ceilings.

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Brick Calculator

Brick counts for standard metric & US brick sizes.

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Gravel Calculator

Tonnes & cubic yards for drives, paths and bases.

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Roof Pitch Calculator

Pitch ratio, angle, grade and rafter length.

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Stairs Calculator

Steps, riser height, tread, run and stringer length.

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Board Foot Calculator

Lumber volume in board feet & cubic metres.

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Wallpaper Calculator

Rolls for EU & US rolls, pattern repeat allowed for.

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Mulch Calculator

Bags & bulk volume for beds and borders.

Construction maths without the unit headache

Most online construction calculators speak only one measurement language. If your plans are in metres and the calculator wants feet — or your lumber is sold in board feet and your room is metric — you end up converting by hand and hoping. Loona Construction Calculators remove that step: flip the unit switch on any tool and every input, default and result changes system, while the maths underneath stays identical.

Every calculator also includes the things real jobs need: a waste and cutting allowance (10% by default, adjustable), standard material sizes for both worlds (1200 × 2400 mm plasterboard and 4 × 8 ft drywall, European and US wallpaper rolls, 25 kg and 80 lb concrete bags), the full formula, and a worked example you can check with a pocket calculator.

Frequently Asked Questions

Why do these calculators offer both metric and imperial?

Most construction calculators online are imperial-only, which leaves European and metric users converting by hand. Every Loona construction calculator has a unit-system switch: metres, litres, kilograms and tonnes, or feet, gallons, pounds and cubic yards — with identical maths underneath, so both systems agree on the same job.

Are the results exact?

They are careful estimates based on the standard formulas shown on each page, with a waste allowance (10% by default) for cuts, spills and uneven ground. Always check critical or structural work against local building codes and, where needed, a professional.

Is it really free?

Yes — every calculator is free, needs no sign-up, and runs entirely in your browser. Your measurements are never sent anywhere; close the page and nothing remains.

Which calculator should I start with?

For a renovation, the usual order is: Paint for the decorating budget, Flooring or Tile for the floors, Concrete for any new slab or base, and Brick or Drywall for walls. Each page links to the related calculators you are likely to need next.