Home & DIY Calculators
Estimate exactly how much material your project needs — paint, tiles, concrete, mulch or wallpaper — from simple room or bed dimensions. Every tool works in metric or imperial, adds a sensible waste allowance, and runs entirely in your browser.
- Paint Calculator Enter your room’s dimensions, the number of coats and your paint’s coverage, and get how much paint to buy
- Tile & Flooring Calculator Enter the area to cover and your tile size, add a waste allowance, and get the number of tiles and boxes to buy.
- Concrete Calculator Enter the length, width and thickness of your slab or footing to get the concrete volume and the number of pre-mix bags to buy.
- Mulch & Soil Calculator Enter your garden bed’s area and the depth you want to cover, and get the mulch or soil volume in cubic yards, cubic metres and bags.
- Wallpaper Calculator Enter your room’s perimeter and height and the roll dimensions, and get how many rolls of wallpaper to buy
- Wheelchair Ramp Calculator Enter the vertical rise and a slope to get the ramp's length, horizontal run and incline angle, with an ADA compliance check.
- Firewood Cord Calculator Measure your neatly stacked woodpile's length, height and depth to see how many cords it holds.
- Gravel & Aggregate Calculator Enter the area to cover and the depth, and get the gravel volume and weight in tonnes
- Drywall & Plasterboard Calculator Enter the wall or ceiling area and your sheet size, add a waste allowance, and get the number of drywall sheets to buy.
- Roofing Calculator Enter your roof’s footprint and pitch, and get the true sloped area, the number of roofing squares and shingle bundles to order.
- Sod & Grass Seed Calculator Enter your lawn area and choose sod or seed: get the number of turf rolls and pallets, or the weight of grass seed to buy.
- Fence Calculator Enter your fence length and post spacing, and get the number of posts, panels or sections, and rails you’ll need.
- Deck Board Calculator Enter your deck dimensions and board size, and get the number of deck boards, the total decking length and the joists needed.
- Board Foot Calculator Enter a board’s thickness, width and length to get its board feet
- Stair Calculator (Rise & Run) Enter the total floor-to-floor rise, a target riser height and the tread depth to get the number of risers, the actual riser height, the run and the stringer length.
- Wall Stud Calculator Enter the wall length and stud spacing to get the number of studs, with extra studs for doors and windows and the plate material.
- BTU Calculator (Air Conditioner Sizing) Enter the room area and a few conditions to estimate the air-conditioner cooling capacity you need, in BTU per hour.
- Roof Pitch Calculator Enter the roof’s rise and run and get the pitch as x-in-12, the angle in degrees, the slope percentage and the rafter length.
- Rebar Calculator Enter your slab dimensions and grid spacing and get the number of bars each way, the total length, the weight for your bar size, and the number of grid intersections.
- Brick & Block Calculator Enter your wall dimensions and pick a brick or block type, and get the number to buy
- Excavation Calculator Enter the dig’s length, width and depth and get the in-ground volume, the soil weight, the loose
- Trim & Molding Calculator Enter the room dimensions and door count, and get the baseboard and crown molding lengths
- Retaining Wall Calculator Enter the wall length and height and your block size, and get the blocks per course, the number of courses, cap blocks and the base gravel volume.
- Paver & Patio Calculator Enter the patio dimensions and your paver size, and get the number of pavers to buy plus the gravel base and bedding sand volumes.
Estimate materials, avoid the extra trip
Every "how much do I need?" question is really one of two: an area job (paint, tiles, wallpaper, drywall) or a volume job (concrete, mulch, soil, gravel). Area = length × width; volume = area × depth. These estimators do that math and turn it into the units you actually buy — litres and tins, tiles and boxes, bags and cubic yards — and each adds a sensible waste allowance for cuts, spills and settling.
Work in metric or imperial, adjust the coverage or bag yield to match your product's label, and round up to whole units. Everything calculates in your browser. For garden-specific spacing and soil, see Gardening & Plants.
Frequently asked questions
Are these home & DIY calculators accurate?
Yes — each is exact area/volume geometry (area = length × width, volume = area × depth), with sensible defaults for coverage, waste and bag sizes that you can override. They estimate materials; always check product labels for the actual coverage and yield.
Do they work in metric and imperial?
Yes — every calculator has a metric/imperial toggle (metres & litres, or feet & gallons), so you can work in whichever units your materials are sold in.
Is my data uploaded?
No. Everything is calculated in your browser and nothing is sent to a server — the tools even work offline.
Why do the tools add a waste allowance?
Because real projects need extra: paint for touch-ups, tiles for cuts and breakages, concrete for settling and spills. The defaults are typical, and you can adjust them to your job.