Mortar Volume Calculator
Calculate the volume of mortar needed for brickwork, blockwork, and masonry projects
Wall Sections
Mortar Volume
Premixed Bags (80 lb)
Estimated Cost
Material Breakdown (Site Mix)
Materials Shopping List
| Material | Quantity | Unit Cost | Total |
|---|---|---|---|
| Total Estimated Cost | |||
Step-by-Step Calculation
Mortar Types and Applications
Mortar type selection depends on the structural requirements and exposure conditions. Each type has a different ratio of Portland cement, hydrated lime, and sand that determines its compressive strength and workability.
| Type | Strength (psi) | Cement : Lime : Sand | Best Use |
|---|---|---|---|
| Type M | 2,500 | 1 : 0.25 : 3.375 | Below-grade, retaining walls, foundations |
| Type S | 1,800 | 1 : 0.5 : 4.5 | At/below grade, patios, structural walls |
| Type N | 750 | 1 : 1 : 6 | General purpose, above-grade exterior walls |
| Type O | 350 | 1 : 2 : 9 | Interior, non-load-bearing, repointing |
| Type K | 75 | 1 : 3 : 10 | Historic restoration only |
Mortar Mix Ratios
The cement-to-sand ratio determines the strength and workability of the mortar. A richer mix (more cement) is stronger but less workable and more prone to cracking. The correct ratio depends on the application and expected loads.
1:3 — High Strength
- • Foundations and footings
- • Below-grade walls
- • High load-bearing applications
- • More cement per volume, higher cost
1:4 — Standard
- • Most common ratio for brickwork
- • Good balance of strength and workability
- • Exterior walls above grade
- • Residential construction standard
1:5 — General Purpose
- • Interior walls and partitions
- • Non-structural applications
- • Good workability
- • Economical mix
1:6 — Low Strength
- • Interior non-load-bearing walls
- • Temporary structures
- • Repointing old masonry
- • Most economical mix
Mortar Coverage Guidelines
Mortar coverage varies based on the unit size, joint width, and wall type. Below are typical coverage estimates for common masonry units with 3/8" joints.
| Unit Type | Mortar per Unit (in³) | Units per 80 lb Bag | Units per ft² of Wall |
|---|---|---|---|
| Modular Brick | ~14 | ~60 | 6.86 |
| Standard Brick | ~14 | ~60 | 6.55 |
| Queen Brick | ~14 | ~60 | 5.76 |
| 8" CMU Block | ~92 | ~9 | 1.125 |
| 6" CMU Block | ~76 | ~11 | 1.125 |
| 4" CMU Block | ~60 | ~14 | 1.125 |
An 80 lb bag of premixed mortar yields approximately 0.5 ft³ (864 in³) of mixed mortar. Actual coverage depends on joint tooling, mason technique, and mortar consistency.
Related Calculators
Note: This calculator provides estimates based on standard mortar joint dimensions and mix ratios. Actual quantities may vary due to joint tooling style, mason technique, mortar consistency, temperature, and humidity conditions. Mortar waste on site typically ranges from 5% to 20%. Always order extra materials to avoid project delays. Consult with a masonry professional for structural applications and local building code requirements.
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