Paint coverage calculator
Start with your paintable area or the paint you have. Set the coverage on your product label and see how coats and extra allowance change the result.
Two useful directions.Net area in. Transparent numbers out.
Read coverage as one coat
A label saying 350 sq ft per US gallon normally describes one coat. Covering 700 sq ft with two coats therefore needs 700 × 2 ÷ 350 = 4 US gallons before extra allowance. With 10% extra, plan for 4.4 gallons, then round to available containers.
In metric, 50 m² × 2 coats ÷ 10 m²/L = 10 L before extra. At 10%, plan for 11 L. A label expressed as 50 m² per 5 L converts to 50 ÷ 5 = 10 m²/L per coat.
When you already have paint
At 10 m²/L, 5 L covers a theoretical 25 m² with two coats. Allowing 10% extra reduces the planning area to 25 ÷ 1.10 = 22.73 m². This reverses the same formula used to estimate paint needed.
The allowance is extra paint relative to the calculated need, not a percentage deducted from the tin. Actual yield depends on the surface, application and product instructions.
A few checks prevent a misleading answer
- Enter net paintable surface area, after doors and windows you will not paint. Floor area is not wall area.
- Use the coverage for your exact finish and surface. If the label gives a range, use a conservative value appropriate to your surface; do not treat the best-case maximum as guaranteed.
- Enter coverage for one coat; the calculator applies your coat count. Do not halve coverage and also choose two coats.
- US liquid gallons are used here, not imperial gallons. Changing units converts the physical inputs.
- Keep different colours, primers and products separate. This quick tool estimates one product at a time.
Understand paint coverage and label ranges →
Need room measurements, openings, primer or several paint groups? Use the main paint calculator. For an editable materials and labor budget, use the interior painting cost calculator.