Free home improvement and DIY calculators
Know exactly how much to buy before you head to the store. Free calculators for paint, flooring, tile, concrete, mulch, gravel, drywall, roofing, fences and decks, with the math shown so you can check it.
Interior
Paint calculator
Gallons of paint and primer for walls and ceilings.
Flooring calculator
Square feet, boxes and cost for laminate, vinyl or hardwood.
Carpet calculator
Square yards to buy from a 12 ft roll, with pad and cost.
Tile calculator
Tiles, boxes, thinset and grout for floors and walls.
Drywall calculator
Sheets, screws, joint compound and tape for a room.
Yard & garden
Mulch calculator
Cubic yards or bags of mulch for garden beds.
Gravel calculator
Cubic yards and tons of gravel, stone or sand.
Topsoil calculator
Soil and compost for raised beds and lawns.
Pavers calculator
Pavers, gravel base and sand for a patio or path.
Fence calculator
Posts, rails, pickets and concrete for a wood fence.
Deck calculator
Deck boards, joists and screws for a new deck.
Building
Concrete calculator
Cubic yards and bags for slabs, footings and posts.
Roofing calculator
Roof squares, shingle bundles and underlayment.
Brick & block calculator
Bricks or concrete blocks and mortar for a wall.
Stairs calculator
Steps, riser height, run and stringer length.
Planning
Square footage calculator
Area of rooms and odd shapes in feet and inches.
AC size (BTU) calculator
What size air conditioner a room needs.
Why use Dollar Math Home?
Buy the right amount. Running short halfway through a job costs you another trip and can leave mismatched batches; buying too much wastes money. Each calculator includes sensible waste allowances that pros use.
The math is shown. Every page explains the formula with a worked example, so you can check the result or adapt it to an unusual project.
Private and free. Every calculation runs in your browser. No sign-up, nothing to download.