These home improvement calculators help you estimate materials before you shop, so you buy close to the right amount the first time. Each one runs in your browser, uses standard rule of thumb figures, and explains exactly how its math works on its own page.
- Paint Calculator
Gallons and quarts for walls and ceilings, with doors, windows and coats taken into account.
- Flooring Calculator
Square footage for one or more rooms, plus waste allowance and the number of boxes to buy.
- Mulch, Soil and Gravel Calculator
Cubic yards, bags and approximate weight for beds, paths and fill at any depth.
- Concrete Calculator
Cubic yards and 40, 60 or 80 lb bags for slabs, patios and post holes.
- BTU Calculator
Room air conditioner and heater size based on area, ceiling height, sun and climate.
- Square Footage Calculator
Total area for one or more rooms or spaces, in square feet, yards, meters and acres.
- Tile Calculator
Tiles and boxes for floors, walls and backsplashes, with grout joints and waste included.
- Wallpaper Calculator
Rolls needed for a wall or room, adjusted for doors, windows and pattern repeat.
- Drywall Calculator
Sheets for walls and ceilings, plus rough amounts of screws, joint compound and tape.
- Roofing Calculator
Roof area from the house footprint and pitch, converted to squares and shingle bundles.
- Fence Calculator
Posts, rails, pickets and bags of concrete for a run of wood fence.
- Deck Board Calculator
Deck boards, linear feet and screws for a rectangular deck surface.
- Stair Calculator
Number of risers and treads, riser height, total run and stringer length.
How to Get Good Results From an Estimate
An estimate is only as good as the measurements you put in. Measure each space twice, write the numbers down, and use feet as the unit. Convert inches to decimals by dividing by 12, so 6 inches becomes 0.5 feet. For odd shaped rooms or beds, break the area into simple rectangles and circles, work out each piece, and add them together. That is more accurate than guessing at an average.
Plan to buy a little more than the bare minimum. Flooring and tile need extra for cuts, concrete needs extra for uneven ground and spills, and soil settles after watering. The calculators include a waste or extra setting where it matters, and they round up to whole bags, boxes and gallons. Leftover material is useful for repairs and touch ups later, and a second trip to the store usually costs more in time than the small surplus costs in money.
Finally, check the label on the product you actually buy. Paint coverage, box sizes, bag yields and appliance ratings vary by brand, and the label always beats a general figure. If a number on the package differs from the default in a calculator, enter the label figure instead. For structural work, whole house heating and cooling, or anything covered by local building codes, use these results as a starting point and confirm the details with a qualified professional or your local building department.