150+ free home project calculators
Calculate materials, quantities & sizes for any home project
Plan with confidence using practical calculators for decorating, flooring, building, landscaping, roofing, heating and more.
Search calculators Find a calculator150+ calculators. Metric and imperial units. Built for DIY and trade projects.
Popular project calculators
Quickly work out the materials and quantities people calculate most often.
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Paint Calculator
Estimate how much paint you need for walls, ceilings and decorating projects.
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Concrete Calculator
Calculate concrete volume for slabs, bases, paths, footings and more.
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Tile Calculator
Work out tile quantities, coverage and an allowance for cuts and waste.
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Gravel Calculator
Estimate gravel volume and quantity for landscaping projects.
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Flooring Calculator
Calculate floor area, waste allowance and the number of packs to buy.
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BTU Calculator
Estimate heating or cooling output for a room using project measurements.
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Decking Calculator
Estimate decking boards, coverage and material requirements for a deck.
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Brick Calculator
Calculate an estimated brick quantity for walls and masonry projects.
What are you working on?
Jump straight into calculators commonly used together for a home project.
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Painting a room
Paint, wall area, ceiling paint and coverage calculators.
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Building a patio
Pavers, gravel, sand, concrete and area calculators.
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Laying flooring
Floor area, packs, tiles, carpet and waste calculators.
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Building decking
Boards, posts, screws, spacing and timber calculators.
Every calculator, organised by project type
Find the right tool faster by choosing the part of your project you are planning.
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Decorating & Walls
Paint, wallpaper, wall area, sheet materials and decorating quantities.
18 calculators
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Flooring & Tiling
Flooring packs, tiles, carpet, underlay and project coverage.
18 calculators
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Concrete, Brick & Masonry
Concrete, blocks, bricks, mortar, reinforcement and masonry materials.
25 calculators
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Garden & Landscaping
Gravel, soil, turf, seed, patios, drainage and landscaping quantities.
25 calculators
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Decking, Fencing & Timber
Deck boards, fencing, posts, timber, fixings and layout calculators.
18 calculators
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Roofing, Insulation & Exterior
Roof area, pitch, insulation, siding, guttering and exterior materials.
18 calculators
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Heating, Cooling & Ventilation
BTU, airflow, heat loss, boiler sizing, ventilation and room planning.
14 calculators
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Measurement & Project Planning
Area, volume, slope, spacing, conversion and project planning tools.
14 calculators
Why people use The Project Calculator
Built to answer the practical question behind most DIY and home projects: how much do I actually need?
Useful inputs only
Enter the measurements that matter, without unnecessary settings.
Metric & imperial
Switch units to match your project, products and measurements.
Clear project results
Get practical quantities, buying estimates and supporting figures you can use.
See how quickly you can estimate a project
The paint example on this page shows the approach used across the site: enter your project measurements, choose your units and get a clear result.
Home improvement calculators for planning materials and quantities
The Project Calculator brings practical home, DIY and construction calculations into one place. Use individual calculators to estimate paint, concrete, tiles, flooring, gravel, bricks, decking, insulation, roofing, heating requirements, measurements and many other project quantities.
Each calculator is designed around a specific task so you can move from measurements to a useful project estimate quickly, whether you are planning a small room update or a larger home improvement job.
Find the calculator for your next project
Search the full collection by material, measurement, room or project type.