How to use the paint coverage calculator
This calculator helps you estimate paint volume and whole-can quantities from area, coats and coverage. It is intended for quantity takeoffs, early budgets and checks against a measured schedule. Start with the dimensions or quantities for one clearly defined item of work. Enter values in the units shown beside each field; millimetres and metres are not interchangeable.
Coverage is a planning input, not a product guarantee. Surface porosity, application method, colour changes and texture can increase consumption. Primer is a separate item.
Worked example
40 m² with two coats at 10 m²/L needs 8 L. With 5 L cans, buy two cans.
Before you order
Compare the result with your drawings and supplier information. Keep the original net quantity separate from allowances, and round purchasing quantities only at the ordering stage. Check whether delivery, labour and related materials belong elsewhere in your estimate. If the drawing or specification changes, update the inputs and record the revised basis instead of reusing an earlier total.
For the concepts behind this calculation, read Unit Rate, Wastage Factor, Takeoff (Quantity Takeoff).