Spray Paint & Aerosol Coverage Calculator

Enter surface area, number of coats, and can size. Select your application technique to account for overspray. Get the exact number of cans to buy. Nothing uploaded.

Can count Overspray adjustment 400/500/750mL cans 3 technique types

Job Details

Cans Required

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aerosol cans
Effective coverage per can-
Total area needed-
Exact calculation-

Learn more: spray paint coverage

FAQ

How many spray paint cans do I need?

A standard 400mL aerosol spray can covers approximately 2.0m² per coat on flat surfaces at optimal distance. For 3D objects, complex shapes, or outdoor use with overspray, effective coverage drops to 1.3-1.7m² per coat. For 3m² with 2 coats at 85% efficiency: 6m² / 1.7m² = approximately 3.5 cans, round up to 4.

Why is the coverage different for 3D objects vs flat panels?

Flat surfaces maximise paint deposition. 3D objects have angles that cause overspray - paint that misses the surface and is wasted. Painting a chair, sculpture, or curved surface can waste 30-50% of the paint in overspray. The calculator applies typical efficiency factors per technique.

How many coats of spray paint should I apply?

Most projects need 2-3 thin coats for good coverage. One thick coat often runs and sags. A primer coat followed by 2 colour coats is the standard approach for automotive or furniture painting. Allow each coat to flash off (15-30 minutes at 20°C) before applying the next.

Last reviewed: June 4, 2026