What this tool does
Multiply the actual paintable area by the coat count and use the product’s coverage per litre to plan the purchase.
How to use it
- Enter the paintable area after excluding large openings.
- Enter coats, the labelled square metres per litre, allowance and can size.
- Review required litres and the rounded-up number of cans.
Formula and method
Base litres = area × coats ÷ coverage per litre. Add the allowance, divide by can size and round up to whole cans.
Example
Painting 40m² twice at 10m²/L requires 8L before allowance. With 10% allowance it needs 8.8L, so 4L cans require 3 cans.
Useful for
- Preparing an interior painting project
- Comparing products by coverage
- Planning multiple coats
Limits and notes
Porosity, surface texture, colour changes, primer, dilution and application losses alter real use. Treat the label’s coverage and surface-preparation instructions as the primary guidance.
Frequently asked questions
Where can I find the coverage value?
Check the container or manufacturer sheet for m²/L under the applicable surface and method.
Does this include primer?
No. Calculate primer and finish paint separately because their coverage rates can differ.