Find My Brick

Lime Mortar Calculator

Estimate the lime and sand needed for brick or block mortar. Choose the wall size, lime type, mix ratio and wastage to get a planning quantity.

Uses the selected brick size and a nominal 10mm mortar joint to estimate the mortar volume.
These are planning densities for estimating weight. The actual product density and bag size vary by manufacturer.
Mix ratios are by volume. Use the mortar specification appropriate to the masonry and exposure.
Please enter valid wall dimensions.

Your estimated materials

—finished mortar
—dry mix volume
—lime binder
—approx. 25kg lime bags
—building sand
—sand weight
Important: This is a planning estimate, not a mortar specification. Lime type and mix should be selected for the existing masonry, exposure and condition. For historic or soft brickwork, check the existing mortar and follow the lime manufacturer's guidance before ordering or mixing.

The calculator uses a dry-volume allowance and planning bulk densities to estimate material quantities. Actual use varies with joint size, brick dimensions, workmanship, sand grading, moisture and the specific lime product.

🧱 Need a sand & cement calculation?Open the existing Sand & Cement Calculator ← Back to Find My Brick

Lime mortar calculator FAQs

Which lime should I use?

NHL 2, NHL 3.5 and NHL 5 have different strength characteristics. The correct choice depends on the masonry and exposure, so the calculator should not be used to select lime type by itself.

Are the quantities exact?

No. They are estimates intended for planning and ordering. Actual mortar consumption depends on brick size, joint thickness, workmanship, sand and the specific lime product.

Can I use this for repointing?

This version is designed for new brick or block mortar quantities. Repointing needs a separate calculation based on the area, joint dimensions and raked-out depth.

What do the 1:2, 1:2.5 and 1:3 ratios mean?

They are volume ratios of one part lime binder to two, two and a half, or three parts sand. Always follow the product and project specification where one is provided.

FindMyBrick provides estimates only. Check quantities and mortar suitability with the lime manufacturer or a qualified professional before use, particularly on listed, historic, load-bearing or exposed masonry.