Primer planning
Paint primer calculator
Calculate primer volume and an optional whole-package recommendation from the net area, product coverage, coats, waste and packages you enter.
Primer planning
Result
How the primer estimate works
Estimate paint primer from a net area and the coverage printed for the exact product and application. Add package sizes only if you want a whole-package recommendation.
How to use it
- Enter the positive net area after making any required deductions.
- Copy coverage and coat guidance from the current label or technical sheet, then enter your own waste allowance.
- Optionally add available can sizes, calculate, and compare the result with the product instructions.
Formula
Theoretical primer = net area × coats ÷ declared coverage. Required primer = theoretical primer × (1 + waste ÷ 100). Whole packages use only the sizes you enter and minimise leftover.
Example
For 10 m², one coat, declared coverage of 5 m²/L and 10% waste: theoretical primer is 2 L and required primer is 2.2 L. With a 2.5 L can, the recommendation is one can with 0.3 L left over.
Assumptions
- Net area already reflects the deductions that apply to your project.
- Coverage, coats, waste and package sizes refer to the exact paint-primer product and application you plan to use.
Limitations
- The calculator does not choose primer type or assess substrate, porosity, compatibility, preparation or drying.
- It is for paint primer, not a tile bonding primer or another specialist coating.
- Prices, stock and product availability are not checked.
Primer questions
Where should I find the coverage value?
Use the current product label or technical sheet for the exact primer, substrate and application method. Do not substitute a universal value.
Can I calculate primer without entering can sizes?
Yes. The required volume is still calculated, but a whole-package recommendation is shown only when valid package sizes are entered.