Calculators
Paint Calculator
Estimate paint, coats, and buy amount from paintable area, coverage, and waste allowance locally in your browser.
Enter the total paintable area in square feet to estimate how much paint to buy, including coats, coverage, and a waste allowance for touch-ups and spills. The calculation runs locally in your browser; your values are not uploaded or stored.
Buy estimate uses 350 sq ft per gallon when coverage is left blank. Check your paint can label because primer, surface texture, and application method change real coverage. This gallons estimate is a planning guide, not a purchase guarantee.
Find how much paint to buy without uploading anything.
Enter the total paintable area in square feet or square meters, the number of coats, an optional coverage per gallon or liter, and a waste allowance to see the exact paint needed and the rounded-up buy amount. Everything runs locally in your browser, so your values are not uploaded or stored.
Frequently Asked Questions
Everything you need to know about this tool, how it works, and privacy.
What does the paint calculator show?
Enter the total paintable area, the number of coats, an optional coverage per gallon or liter, and a waste allowance. The calculator returns the exact paint needed and the buy amount rounded up to whole gallons or liters with the calculation shown. For example, 400 sq ft with 2 coats at 350 sq ft per gallon and 10% waste needs about 2.51 gallons, so buy 3 gallons.
Which formula does the paint calculator use?
It uses raw paint = (paintable area x coats) / coverage per unit, then total = raw x (1 + waste percent / 100), and buy amount = total rounded up to the next whole gallon or liter. Leaving coverage blank uses 350 sq ft per gallon in imperial mode or 10 square meters per liter in metric mode.
Which inputs are accepted?
Enter a paintable area greater than zero through 1000000000, a whole-number coat count from 1 to 10, an optional coverage greater than zero through 1000000, and a waste allowance from 0 to 100 percent (blank means 10). Decimal areas and coverage values are accepted. Zero, negative numbers, non-numeric text, and values outside these limits show a clear error instead of a result.
Do my numbers stay private?
Yes. The calculation and copy action run locally in your browser. CodeASystem does not upload or store the values you enter.