Mortar Calculator

How it works

1. 1Enter the wall area and select the wall type (half-brick, one-brick, or blockwork) — each has a standard mortar volume per m².
2. 2Choose your mortar mix ratio (1:4, 1:5, or 1:6 cement:sand). A richer mix uses more cement and gives higher strength.
3. 3The calculator applies a 1.54 dry-to-wet factor and outputs wet mortar volume, cement bags, sand volume, and cement mass.

Use cases

• Estimating materials before ordering for a garden wall or extension project.
• Comparing how mortar demand changes between single-skin and double-skin brickwork.
• Checking how the mix ratio (1:4 vs 1:6) affects cement bag count for budgeting.

Frequently asked questions

What mortar volume per m² does each wall type use?

Half-brick (single skin) walls use roughly 0.025 m³/m², one-brick (double skin) walls about 0.05 m³/m², and blockwork about 0.012 m³/m². These assume 10 mm joints and typical waste.

Why apply a 1.54 bulking factor?

Dry cement and sand combine with water and compact, so you need more dry volume than the final wet mortar. Multiplying by 1.54 covers this; 0.1 m³ of wet mortar needs roughly 0.154 m³ of dry materials.

How do I choose between a 1:4 and a 1:6 mix?

A 1:4 mix is stronger — suited to engineering bricks, below-ground work, or exposed conditions. A 1:6 mix is softer and more workable, preferred for internal or lightweight blockwork.