Measure and MendStart measuring

Know how much your home project really needs.

Plan materials, compare options, and see how every estimate was worked out.

Paint calculator

Measure the wall perimeter and height, then subtract the actual total area of doors and windows.

3 one-gallon cans

374 sq ft of paintable wall area × 2 coats = 748 coated sq ft.

The cited 350–400 sq ft/gal range is 2–3 whole cans. The main result uses the coverage shown on your can.

View project plan

Calculate once to save this result.

See the formula and assumptions

(2 × (length + width) × height − measured openings) × coats ÷ coverage. Purchase quantities are rounded up only at the final can step. Surface condition and application method can change real coverage.

Built for the job in front of you

Enter your measurements and we’ll show the assumptions, source values, and whole-package rounding.

Paint

Room walls, coats, measured openings, and the coverage printed on your can.

Open calculator

Bagged concrete

Slabs, footings, or post holes using the published yield for the bag size you choose.

Open calculator

Attic insulation

U.S. or Canadian label values, attic area, bag coverage, and installed depth.

Open calculator

Drywall sheets

Measured wall or ceiling area, the sheet size you choose, and optional extra material.

Open calculator

Deck boards

Deck dimensions from your plan, actual board face width, required gap, and extra material.

Open calculator

Reference values used by the calculators

ProjectCited inputWhat changes it
Interior paint350–400 ft²/galProduct and surface
Concrete mix0.30 / 0.45 / 0.60 ft³Selected bag
Loose-fill insulationExact label rowMarket and R-value
Drywall sheetsActual panel face areaSelected panel and layout
Deck boardsActual face width + gapApproved layout

Always use the current product label or approved project instructions when they differ.

Browse all calculators

Catch small problems before they become expensive repairs

Choose a season to see a short list of things worth checking around the house.

Find the official climate profile

Questions homeowners ask before starting

01How much paint do I need for a room?02How do I calculate bags of concrete?03How do I calculate gypsum panel count?04Which deck surfaces belong in a finish estimate?
Browse all 16 guides