Mortar Calculator

Mortar binds bricks and blocks. Enter the volume of wet mortar and the mix to get the cement and sand.

Wet mortar volume in
About 0.25 to 0.3 m³ of mortar per m³ of brickwork.
Results update as you type.

Cement

5.47 bags

274 kg

Sand
1.14 m³ (40.3 cft)0.4 brass
Dry volume
1.33 m³ (47 cft)

Richer mixes (1:3, 1:4) are used for half-brick walls and pointing; 1:6 is common for full-brick walls.

About this calculator

As a guide, a cubic metre of brickwork takes about 0.25 to 0.3 m³ of mortar.

How to use it

  1. Enter the wet mortar volume.
  2. Choose the mix.
  3. Read cement and sand.

The formula

Dry volume = wet × 1.33; cement = dry ÷ (1 + sand parts)
1.33
allows for voids and bulking of dry sand

Worked example

1 m³ of 1:6 mortar

  1. Dry = 1.33 m³; cement = 1.33 ÷ 7 = 0.19 m³ = 5.47 bags.
  2. Sand = 1.14 m³ (40.3 cft).

What the result means

Use the brick calculator to work out mortar from a wall size.

Assumptions

  • Volume batching.

Limitations

  • Factor values vary slightly between references.

Frequently asked questions

How many cement bags for 1 m³ of 1:6 mortar?

About 5.5 bags.

Which mix for plaster?

1:4 to 1:6, see the plaster calculator.

Why 1.33?

To convert wet volume to the dry materials needed.

Last reviewed on 3 October 2026. Found a mistake? Tell us.