Mortar Volume Calculator – Calculate Mortar Needed for Bricklaying & Tiling

Get precise mortar quantities for your construction project with our Mortar Volume Calculator. Enter wall area, joint width and depth, and brick type to calculate the exact volume needed — saving material and reducing waste.

Wall Length

Wall Height

Unit

Brick Size

Joint Width (mm)

Joint Depth (mm)

Waste Factor (%)

Mortar Estimate

Enter wall dimensions and click Calculate to see mortar estimate

How to Use This Mortar Volume Calculator

Enter wall dimensions

Input the length and height of your wall. Select meters or feet depending on your measurement system.

Select brick type and joint specifications

Choose your brick size from the dropdown. Enter joint width and depth (10mm is standard for most applications).

Calculate and review results

Click Calculate to see mortar volume in cubic meters, weight in kg, and number of 25kg bags needed.

Mortar Joint Standards by Application

Application	Joint Width	Mortar Type
Interior brick walls	10mm	Type N (1:1:6)
Exterior load-bearing	10-12mm	Type S (1:0.5:4.5)
Below grade/foundations	10mm	Type M (1:0.25:3)
Historic restoration	6-10mm	Type O or lime mortar
Block/CMU walls	10-12mm	Type N or S
Stone masonry	12-20mm	Type N

Understanding Mortar Volume Calculations

How Mortar Volume Is Calculated

Mortar fills the gaps between bricks — both horizontal bed joints and vertical head joints. The calculator determines how many bricks fit in your wall area, then multiplies by the mortar volume needed per brick. Joint width and depth directly affect the total volume. A 10mm joint uses roughly 0.6-0.8 liters of mortar per brick depending on brick size.

Why Waste Factor Matters

Not all mortar makes it into the joints. Some falls on the ground, some dries out in the hawk, and some gets over-applied. A 10% waste factor is standard for experienced masons. First-time DIYers should plan for 15-20% waste. Mortar cannot be returned once mixed, so it is better to have a little extra than to run short mid-wall.

Mortar Density and Bag Coverage

Wet mortar weighs approximately 2000 kg per cubic meter. Standard pre-mix bags contain 25kg of dry mortar. One 25kg bag yields about 0.012-0.015 cubic meters of wet mortar, enough for roughly 20-25 standard bricks with 10mm joints. Always check the manufacturer's coverage rating as formulations vary.

Tips for Accurate Mortar Estimation

Measure twice, order once

Double-check wall dimensions before calculating. Add 5% extra for cutting waste on partial bricks.

Mix small batches

Mortar starts setting in 2-3 hours. Mix only what you can use in one session to avoid waste.

Consider weather conditions

Hot weather speeds up drying. Cold weather slows curing. Plan your work accordingly and protect fresh mortar.

Use consistent joint tooling

Tool joints when thumbprint-hard. Consistent joint depth ensures uniform appearance and weather resistance.

Frequently Asked Questions

How much mortar do I need per brick?

For standard bricks with 10mm joints, plan on 0.6-0.8 liters of mortar per brick. This equals roughly 1.2-1.6 kg of wet mortar. Larger bricks or wider joints increase consumption. A 25kg bag of dry mortar typically lays 20-25 standard bricks.

What is the best mortar mix for bricklaying?

Type N mortar (1 part cement, 1 part lime, 6 parts sand) works for most above-grade brick walls. It offers good bond strength and flexibility. For load-bearing or below-grade work, use Type S (1:0.5:4.5) for higher compressive strength.

How wide should mortar joints be?

Standard brick joints are 10mm (3/8 inch). Acceptable range is 6-15mm depending on brick type and application. Wider joints weaken the wall and use more mortar. Historic brickwork often used narrower joints (6-8mm) for a tighter appearance.

Can I use old mortar for repairs?

Match the original mortar type when repointing historic masonry. Modern Portland-based mortars are harder and can trap moisture, damaging old bricks. For pre-1900 buildings, consider lime-based mortar that allows the wall to breathe and move naturally.

How long does mortar take to cure?

Mortar sets enough to tool joints in 1-2 hours. It reaches initial cure in 24-48 hours. Full cure takes 28 days. Keep mortar moist during the first week for proper curing. Avoid heavy loads or stress on the wall for at least 7 days after laying.

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