Measure and MendStart measuring

Know how much your home project really needs.

Plan materials, compare options, and keep your home in good repair with calculations you can inspect.

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 entered 350 sq ft/gal label value.

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

Start with a measurement, then see the assumptions, purchase rounding, and sources behind the answer.

Current planning inputs

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

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

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Keep the work from becoming a repair

Seasonal prompts turn small observations into a source-scoped maintenance rhythm.

Find the official climate profile

Questions homeowners ask before starting

01How much paint do I need for a room?02Should I subtract windows and doors when estimating paint?03Does a second coat double the amount of paint?04How do I calculate bags of concrete?
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