Mortar Calculator: Cement and Sand for 1:3, 1:4, 1:5 and 1:6
Enter how much mortar you need, or how much brickwork you are building, choose the cement–sand ratio and get bags of cement and sand in m³ and cft.
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Cement (50 kg bags)
8bags
- Mortar (wet)
- 1 m³ · 35.3 cft
- Cement weight
- 383 kg
- Sand
- 1.06 m³ · 37.6 cft
Estimate only, based on standard thumb rules. Confirm quantities with your engineer or contractor before you buy.
Show working
- V dry = 1 × 1.33 = 1.33 m³
- Cement = 1.33 × 1/5 × 1440 = 383 kg ÷ 50 = 7.66 → 8
- Sand = 1.33 × 4/5 = 1.064 m³
How to use
- Choose whether you know the mortar volume or the brickwork volume.
- Enter the volume in m³ or cft.
- Pick the mix ratio to see cement bags and sand.
Good to know
Dry mortar = wet volume × 1.33 (it covers bulking of sand and some wastage). Cement = dry volume × 1 ÷ (1 + sand parts) × 1440 kg/m³ ÷ 50 kg. Sand = dry volume × sand parts ÷ (1 + sand parts).
For brickwork with modular bricks and 10 mm joints, mortar is about 23% of the wall volume (1 − 500 × 0.19 × 0.09 × 0.09). Traditional larger bricks with thicker joints often need 25–30%; change the share if your mason’s joints are thicker.
Common uses in India: 1:3 for pointing and waterproof work, 1:4 for half-brick walls and external plaster, 1:6 for 9 inch brickwork and internal plaster. Use clean, graded sand; silt and too much water weaken mortar more than a slightly leaner mix.
Questions
How much cement in 1 m³ of 1:6 mortar?
1 × 1.33 = 1.33 m³ dry; cement = 1.33 ÷ 7 = 0.19 m³ × 1440 = 274 kg, about 5.5 bags (6 when rounded up).
How much mortar for 1 m³ of brickwork?
About 0.23 m³ wet with modular bricks; 0.25–0.30 m³ with traditional bricks and thicker joints.
Which ratio is strongest?
1:3 has the most cement and is strongest; 1:6 is leaner and cheaper. Stronger is not always better for brickwork; follow your engineer.
What dry factor should I use?
1.33 is common; some estimates use 1.27 plus separate wastage. You can change it under More options.
Does it give water quantity?
No. Water depends on sand moisture and workability; masons add it gradually.