Worked example
How Much Paint for a Bedroom with Two Coats?
This example uses a 12 ft by 14 ft bedroom with two coats, one door, and two windows to show a more realistic paint estimate.
Calculator inputs
Paint Calculator Results
Results update in your browser as you edit inputs. They are planning estimates, not complete shopping lists.
Enter project dimensions to calculate material quantity.
Inputs used in this example
- Bedroom size: 12 ft by 14 ft.
- Wall height: 8 ft.
- Openings: one 20 sq ft door and two 15 sq ft windows.
- Coats: 2, with 350 sq ft per gallon coverage.
Expected output
The calculator estimates 416 sq ft of wall area, 366 sq ft after opening deductions, about 2.09 gallons before rounding, and a 3 gallon whole-gallon equivalent.
When to adjust this example
- Use the paint label coverage if it differs from 350 sq ft per gallon.
- Increase waste for textured, patched, raw, or high-contrast walls.
- This example estimates wall paint only, not primer, trim paint, ceiling paint, or supplies.
Formula explanation
- Find room perimeter with 2 x (12 + 14).
- Multiply by wall height for wall area.
- Subtract the entered door and window area.
- Multiply by two coats, divide by paint coverage, and round up for buying.
Main calculator
Use the full Paint Calculator to change dimensions, waste factor, and optional user-entered unit price.
FAQ
Why does the calculator show a rounded gallon value?
Paint is bought in container sizes, so the rounded whole-gallon equivalent is a safer planning quantity than a fractional gallon.
Can I estimate one coat instead?
Yes. Change number of coats from 2 to 1 in the embedded calculator.