Home & Construction Calculators
Ordering too little material stalls a project; ordering too much wastes money. These calculators turn your measurements into the quantities suppliers sell by — gallons of paint, boxes of flooring, sheets of drywall, deck boards, fence pickets, cubic yards of concrete or gravel, squares of roofing — and include sensible allowances for waste.
They are meant for planning and budgeting. For structural work, always confirm quantities and specifications with your supplier or a qualified contractor.
Home & Construction tools
Concrete Calculator
Free concrete calculator for slabs, footings, columns, and stairs. Get cubic yards and cubic meters plus 40, 60, and 80 lb bag counts with 10% waste.
BTU Calculator
Free BTU calculator to size an air conditioner or heater for any room. Enter dimensions, ceiling height, insulation, and sun exposure to get BTU and tons.
Square Footage Calculator
Free square footage calculator for rooms, yards, and complex shapes. Calculate area in sq ft, sq m, and acres.
Stair Calculator
Free stair calculator that finds riser height, tread depth, number of steps, stringer length, and stair angle from your total rise, with code checks.
Roofing Calculator
Free roofing calculator that turns roof size and pitch into shingle bundles, underlayment rolls, ridge caps, drip edge, and nails, plus a cost estimate.
Tile Calculator
Free tile calculator for floors, walls, and backsplashes. Enter area, tile size, and grout width to get tiles and boxes needed with waste, plus cost.
Mulch Calculator
Free mulch calculator for rectangle, circle, or triangle beds. Enter area and depth to get cubic yards and 2 cu ft bags needed, with an optional cost.
Gravel Calculator
Free gravel calculator for driveways, paths, and landscaping. Get cubic yards and tons of stone for rectangular, circular, or triangular areas, plus cost.
Board Foot Calculator
Board foot calculator for lumber: enter thickness, width, length and quantity to get board feet, cubic meters and optional cost.
Deck Calculator
Deck calculator: estimate deck boards, joists and screws from your deck size, board width, gap, board length and joist spacing.
Drywall Calculator
Drywall calculator: find how many 4x8, 4x10 or 4x12 sheets you need for walls and ceilings, plus joint compound, tape and screws.
Fence Calculator
Fence calculator: estimate posts, rails, pickets and bags of concrete for a wood fence from its length, post spacing, height and gates.
Flooring Calculator
Flooring calculator: add up one or more rooms, include 10% or 15% waste, and see how many boxes of laminate, vinyl plank or hardwood to buy.
Insulation Calculator
Insulation calculator for attics and walls: find blown-in depth and bags or batt bags for your target R-value, with DOE attic R-value recommendations.
Paint Calculator
Free paint calculator: estimate how many gallons or quarts of paint you need for walls and ceilings, minus doors and windows, for any number of coats.
Paver Calculator
Paver calculator: count pavers for a rectangular or round patio, plus gravel base and bedding sand in cubic yards and tons.
Retaining Wall Calculator
Retaining wall calculator: estimate wall blocks, courses, cap blocks and gravel base and backfill for a segmental block wall.
Wallpaper Calculator
Free wallpaper calculator: work out how many rolls you need from room size, doors, windows, roll size and pattern repeat using the strip method.