Mortar Calculator
Calculate mortar needed for brick and block masonry work. Includes all mortar types with mix ratios, coverage rates, and material quantities.
Calculate mortar needed for brick and block masonry work. Includes all mortar types with mix ratios, coverage rates, and material quantities.
Mortar fills joints between bricks and blocks. Joint thickness and unit size affect mortar volume needed.
A mortar calculator is most useful when the mix type matches the wall or repair application. Type S is common in residential masonry, but below-grade work, historic repair, and lighter interior applications do not all use the same mortar classification.
Type M mortar is the highest-strength common mortar class and is generally used where high compressive demand or below-grade conditions are involved.
Type S mortar is a common general-purpose choice for residential brick and block work because it balances strength and workability for many above-grade applications.
Type N mortar is often used for general above-grade masonry and for situations where a somewhat softer, more workable mortar is appropriate.
Type O mortar is a lower-strength mix generally associated with certain interior or historic repair conditions where a softer mortar is required.
Pre-mixed: bagged mortar with a simpler setup process and more consistent batching for smaller jobs.
Site-mixed: mortar blended from separate materials on site, often used when more volume or more mix control is needed.
Standard coverage rates:
These rates assume standard joint thickness and reasonably consistent unit size. Thicker joints, irregular units, and jobsite waste can all increase the final order quantity.
Mortar working time, retempering limits, weather conditions, and cure time all affect installation quality. Hot, dry, cold, or freezing conditions can change the way the mix performs and the time available to use it.
| Type | Compressive Strength | Mix Ratio (C:L:S) | Primary Use | Workability |
|---|---|---|---|---|
| Type M | 2500 psi | 1:0.25:3 | Structural, heavy-duty, below-grade | Stiff |
| Type S | 1800 psi | 1:0.5:4.5 | General-purpose, most common | Good balance |
| Type N | 750 psi | 1:1:6 | Interior, above-ground, general | Workable, flexible |
| Type O | 350 psi | 1:2:9 | Interior non-load-bearing, heritage | Very workable |
Type S is stronger (1800 psi), better for exterior and load-bearing. Type N is softer (750 psi), more flexible, better for interior or repointing old brick. S if it's structural, N if it needs to bend.
Standard bricks with 1/2" joints: 25-30 bags per 1000 bricks (60-lb bags). Thicker joints need more. Always overestimate a bit — mortar dries and you can't add more later.
Once. Add a little water before the mortar sets and you can keep working. But do it twice and you're adding too much water, which weakens the mortar. Mix small batches so you don't waste it.
1/2" is standard. Thin brick (precision-cut) takes 3/8". Handmade rustic brick wants 5/8" or thicker. Consistent joints matter more than the exact size — keep them even across the whole wall.
No. Mortar is cement + lime + sand (no rocks). Concrete is cement + sand + gravel. Mortar binds bricks. Concrete is poured as its own thing. Different materials, different jobs.
