Primer Coverage Calculator
Calculate the amount of primer needed for a surface based on area, spread rate, and number of coats.
How to Use the Primer Coverage Calculator
- Enter the total surface area in m².
- Enter the primer spread rate in m² per litre.
- Enter the number of coats.
- Click Calculate to see litres needed and can count.
Casi d'Uso
- •Estimating primer for interior and exterior painting projects.
- •Planning material purchases for renovation work.
- •Calculating primer for new drywall or plaster surfaces.
- •Cost estimation for painting contractors.
Formula
Primer (L) = Surface area / Spread rate × Number of coats. Cans = ⌈Litres / 5⌉.
Domande Frequenti
What is a typical primer spread rate?
Most primers cover 10–14 m² per litre on smooth surfaces; porous or rough surfaces reduce coverage to 6–10 m²/L.
Do I always need two coats of primer?
One coat is usually sufficient on previously painted surfaces; bare or porous surfaces typically require two coats.
Is it free?
Yes, all calculators on OhMyCalc are completely free.