Free DIY & home improvement calculators
Know exactly how much to buy — before you head to the store.
Concrete, paint, decking, flooring, fencing and more. Enter a few measurements and get an instant answer, a shopping list and the math behind it.
Popular: Concrete BagsDrywallGravelPaversStairsBoard Feet
- 100% free
- No sign-up
- Formulas shown
- US & metric units
Most popular calculators
See all 20 →- Concrete Slab Calculator Estimate cubic yards, cubic meters and bags of concrete for a slab, patio or pad — with waste factor, the formula and a shopping list.
- Paint Calculator Work out gallons or liters of paint for a room, with doors, windows, coats, ceiling and primer — plus the tin sizes to buy.
- Deck Board Calculator Work out how many deck boards, joists, screws or hidden clips you need for a deck, using real board widths, gaps and stock lengths.
- Flooring Calculator Calculate boxes of laminate, vinyl plank or hardwood flooring for any room, with layout waste, underlay and baseboard length.
- Fence Calculator Estimate fence posts, rails, pickets or panels and post-hole concrete for any fence length, with gates and real post sizes.
- Mulch Calculator How much mulch do you need? Get cubic yards, cubic meters and the number of 2 or 3 cu ft (50/70 L) bags for any bed and depth.
- Tile Calculator Count floor or wall tiles and boxes, with grout joints and extra for straight, offset, diagonal or herringbone layouts.
- Roofing (Shingle) Calculator Turn a house footprint and roof pitch into roof area, roofing squares and shingle bundles, plus starter, ridge cap and underlayment.
Browse by project
- Concrete Slabs, patios, pads and bagged premix. 2 calculators →
- Paint & Wallpaper Walls, ceilings, primer, coats and wallpaper rolls. 2 calculators →
- Tile Floor and wall tile, boxes and adhesive. 1 calculator →
- Flooring Laminate, vinyl plank and hardwood. 1 calculator →
- Roofing Shingles, squares and pitch. 1 calculator →
- Landscaping Mulch, gravel, topsoil and pavers. 4 calculators →
- Decking Deck boards, joists and fasteners. 1 calculator →
- Fencing Posts, rails, pickets, panels and post concrete. 1 calculator →
- Drywall (Plasterboard) Sheets, mud, tape and screws. 1 calculator →
- Framing & Lumber Board feet, stairs and timber. 2 calculators →
- Masonry Bricks, blocks and mortar. 1 calculator →
- Conversions Area, volume, feet-inches and units. 3 calculators →
Why DIYers trust our numbers
The math is always shown
Every result has a “Show the math” panel with each step, plus the formula and assumptions on the page.
How we calculateReal product sizes
Bag yields, tin sizes, sheet and board lengths come from manufacturer data — and you can override every default.
Our sources policyTested, rounded up
Each calculator is checked against hand-worked examples. Quantities always round up to whole bags, boxes and sheets.
About DIYCalcLabProject guides
All 12 guides →- GuideHow Much Concrete Do I Need? A Step-by-Step GuideWork out concrete volume for slabs, footings and post holes in cubic yards, cubic meters and bags — with worked examples, waste allowances and ordering tips.
- GuideHow Much Paint Do I Need for a Room?Calculate wall area, deduct doors and windows, choose coverage and coats, and buy the right mix of gallons, quarts or liter tins — with US and UK examples.
- GuideHow to Plan a Deck: Size, Layout and MaterialsPlan a deck from site to materials list: choosing size around board lengths, board direction, gaps, joist spacing, footings and the permits you may need.
- GuideMulch, Gravel and Topsoil: How Deep Should Each Layer Be?Recommended depths for mulch, decorative gravel, sub-base and topsoil, how much one cubic yard or cubic meter covers, and how to convert volume to bags and tons.
All 20 calculators
- Concrete Slab Calculator
- Concrete Bag Calculator
- Paint Calculator
- Tile Calculator
- Flooring Calculator
- Square Footage Calculator
- Mulch Calculator
- Gravel Calculator
- Drywall Calculator
- Roofing (Shingle) Calculator
- Deck Board Calculator
- Fence Calculator
- Topsoil Calculator
- Paver Calculator
- Brick Calculator
- Board Foot Calculator
- Stair Calculator
- Wallpaper Calculator
- Cubic Yard Calculator
- Feet and Inches Calculator