ConverterHub

Ceiling Paint Calculator

Enter the ceiling area, coats, and coverage to estimate the paint needed.

Result

1.03 gal
3.89 L
180.00 sq ft

How it is calculated

The tool uses gallons = area × coats ÷ coverage, with the ceiling area in square feet, the number of coats and the paint's coverage in square feet per gallon. If you leave coats empty it assumes 2, and if you leave coverage empty it assumes 350 sq ft per gallon. Litres are gallons × 3.785 (US gallons). Area, coats and coverage must all be above zero. The result is the exact amount with two decimals and is not rounded up to a full can, so you still choose the next can size yourself. It does not subtract light fixtures or skylights, add waste, or allow for rough or unprimed surfaces that soak up more paint.

Worked example

A ceiling measures 12 ft × 15 ft, so the area is 180 sq ft. You plan 2 coats of paint that covers 350 sq ft per gallon. Total area to cover: 180 × 2 = 360 sq ft. Gallons: 360 ÷ 350 = 1.03 gal. Litres: 1.0286 × 3.785 = 3.89 L. A 1 gallon can falls just short, so you would buy 2 gallons or a 1 gallon plus a quart.

Try this example →

Common mistakes

  • Entering the area in square metres. The tool expects square feet, and 17 m² is about 180 sq ft, so the unconverted figure would give a result about ten times too small.
  • Using the coverage printed for walls or primer. Coverage varies by product and surface, and rough or unprimed ceilings take more paint than the label's 350 sq ft.
  • Buying exactly the calculated amount. 1.03 gal is just over a gallon, and running short partway through risks a colour-batch mismatch, so round up.
  • Forgetting that coats multiply the amount. Leaving coats empty means 2, so a 1-coat job must be entered as 1.
  • Measuring the ceiling by the room's floor area on a vaulted or sloped ceiling. The painted surface is larger than the floor underneath it.

About this calculator

Estimating ceiling paint starts with the ceiling’s area (length × width), since paint cans are rated by coverage per gallon — typically around 350–400 square feet for one coat on a smooth, primed ceiling. Dividing the area by the coverage rate gives the gallons needed for a single coat, and multiplying by the number of coats (most ceilings need two, especially with flat/matte finishes that show roller marks more easily) gives the total.

Ceilings often need slightly more paint than walls of the same area because flat ceiling paint is thicker and less forgiving of thin application, and painters round up to the next full can to avoid a mid-job color-batch mismatch. Defaults of 2 coats and 350 sq ft per gallon apply when those fields are left blank, and the result should be rounded up to a full can when buying.

Was this helpful?

You can pick up to 3 reactions.

Comments

  • Be the first to comment.

Popular calculators

Loan Calculator

Monthly payment, total interest and full amortization schedule.

Percentage Calculator

Percent change, percent of, and ratio calculations.

Discount Calculator

Calculate final price, savings, and discount amount.

BMI Calculator

Body mass index from height and weight (metric or imperial).

Age Calculator

Compute your exact age in years, months and days from a birth date.

Compound Interest Calculator

Calculate the final amount and interest earned with compounding.

All Calculators