Start with the dimensions

Area & volume calculators

Area and volume calculators turn field measurements into the units used by stores, suppliers and contractors. Area describes a flat surface in square feet, while volume adds depth or height and is expressed in cubic feet or cubic yards. Measure each section separately, keep every input in the same unit system, then add a realistic waste allowance for cuts, settlement or irregular edges.

4 working calculatorsUS customary unitsReviewed July 23, 2026

Choose the calculation you need

Start with the material or decision in front of you.

Each tool performs a different takeoff or conversion. Open the closest match, enter real measurements, then review the stated assumptions before using the result to buy material.

square footage calculator

Square Footage

Calculate square footage for one or multiple equal spaces, then add a custom waste allowance for accurate flooring, paint, or material planning.

Open calculator wall square footage calculator

Wall Area

Find net wall square footage after doors and windows, then add waste for paint, drywall, paneling, tile, or wallpaper purchases.

Open calculator cubic yard calculator

Cubic Yards

Calculate cubic yards from project length, width, and depth in inches, including optional waste for soil, gravel, mulch, or concrete.

Open calculator stair calculator

Stair Layout

Plan straight stairs from total rise, maximum riser, tread depth, and width; calculate risers, treads, total run, slope, and stringer span.

Open calculator

How should you use a project calculator?

Begin with finished dimensions from the actual project area, not a plan that may have changed. Break irregular spaces into simple rectangles, triangles or individual runs and calculate each one separately. Keep units consistent, and measure openings, transitions and obstructions that materially change quantity.

The calculator result is a planning takeoff. Suppliers may sell only whole bags, boxes, panels or stock lengths, so purchase quantities are rounded up. Product-specific coverage, local codes, installation methods and site conditions remain the final authority.

Why does the waste allowance matter?

Waste covers cuts, breakage, unusable offcuts, settlement and measurement variation. A simple rectangular project may need only 5% extra, while diagonal layouts, complex roofs, patterned tile and many corners can require 10–15% or more. The right allowance depends on the material and layout, not a universal rule.

Keep unopened returnable packages separate when a retailer permits returns. For batch-sensitive finishes such as tile, flooring or brick, retaining a small matching surplus can also make future repairs easier.