Project category
Painting & Walls calculators
Paint coverage and wall finish calculators.
- Baseboard and Trim Calculator with WasteMeasure the room perimeter or enter a checked wall run, subtract actual no-baseboard openings, add your chosen cut allowance, and round to the stock length sold.
- Paint Calculator for 2 Coats Including CeilingEnter room dimensions in feet, choose two wall and ceiling coats, and get separate gallon and can counts for wall paint and ceiling paint. Door and window deductions apply only to the walls, while each product keeps its own coverage, can size, and optional price.
How these painting & walls calculators work
Each calculator starts from site measurements in feet and inches, converts them with a tested formula, shows the exact quantity and your waste allowance as separate lines, then rounds up to the package or order unit you actually buy. Prices are optional and always entered by you, so the estimate reflects your supplier rather than a national average.
Painting & Walls measuring guides
Step-by-step guides with worked examples and reference tables for United States.
- How to Measure a Room for PaintMeasure wall area, deduct doors and windows, choose coats, and prepare a paint shopping estimate without guessing at the store.
- How to Measure Ceilings and Trim for PaintMeasure ceiling area in square feet, record trim in linear feet, and set the paint scope for doors and windows before you estimate.
- How Much Paint Primer Do You Need? Coverage PlanningFind out how much paint primer you need by calculating coverage from the product label separately from the topcoat, then round each up to a container.
- Room Paint Measurement WorksheetA printable fill-in worksheet for wall lengths, heights, openings, and coats, so every number is on paper before you calculate or shop.
- How Much Paint for a House ExteriorMeasure the body as perimeter times height to the eaves, add each gable triangle, deduct only large openings, and paint trim as a separate calculation.
- How Much Does a Gallon of Paint Cover?A gallon covers about 350–400 sq ft per coat on the label, but far less on the wall once you count two coats, surface texture, and whole-can rounding.
- How Much Paint for Kitchen CabinetsMeasure every face you will coat, count both faces of each door, enter it as a direct area, and keep coats and primer to the product's directions.