How to use this calculator
Measure the exposed brick area you intend to coat, enter the product’s rated area coverage per gallon per coat, and select your planned number of coats. Adjust the absorption multiplier based on product guidance and a test area—not on appearance alone.
The calculation explained
Gallons = exposed area × coats × absorption multiplier × (1 + extra allowance ÷ 100) ÷ rated area per gallon per coat. Containers are rounded up to complete cans.
Check these details before ordering
- Measure only the brickwork receiving limewash and account for excluded openings.
- Use a sample patch to compare theoretical versus actual usage.
- Check manufacturer instructions for exterior exposure and substrate preparation.
Frequently asked questions
What does an absorption multiplier of 1.25 mean?
It is a planning scenario that assumes 25% more material than the product-rated usage. It is not a measurement of a particular brick.
Does this tool calculate mortar coverage?
The estimate covers your measured brick-and-mortar surface as a whole if both receive treatment.
Can it estimate an exterior wall?
You can estimate materials by area, but confirm product suitability and surface preparation for exterior exposure.
Read the related guide
For more context, see How to Read Paint and Decorative Plaster Coverage Rates. It explains practical assumptions that a calculator cannot confirm for your individual project.