The number of bags of cement needed to make 1 cubic meter (m3) of concrete depends on the mix ratio of cement, sand and aggregate you’re using and the size of the cement bags. Typically, for a standard mix of concrete, which is 1:2:4 (cement:sand:gravel), you would need around 13 25kg bags of cement for 1 cubic meter of concrete.

Mixture of Portland cement, sand, gravel (aggregate), water with approved ingredients are used to form concrete paste. The concrete are used for many application like casting of slab, beam, column, retaining wall, flooring, and etc. Water/ cement ratio plays important role in increasing or decreasing compressive strength of concrete. It is inversely proportional to concrete strength.

The common mixing ratio for concrete is 1:2:4 (1 part cement mixed with 2 parts sand and 4 parts aggregate), 1:3:6 (1 part cement mixed with 3 parts sand and 6 parts aggregate), 1:2: 3 (1 part cement mixed with 2 parts sand and 3 parts aggregate) and 1:4:8 (1 part cement mixed with 4 parts sand and 8 parts aggregate).

**Here’s how you can calculate quantity of sand, cement and aggregate to make 1 m3 of concrete at 1:2:4 mix:**

- Estimate dry volume of concrete: Dry volume of concrete = Wet volume × 1.54 = 1m3 × 1.54 = 1.54 m3, means to prepare 1m3 of concrete you may need 1.54 m3 of dry ingradients of sand, cement and aggregate.
- Determine proportion of cement, sand and aggregate: Since the mix ratio is 1 part cement mixed with 2 parts sand and 4 parts aggregate, so total proportion = 1 + 2 + 4 = 7, thus parts of cement = 1/7, parts of sand = 2/7, and parts of aggregate = 4/7.
- Estimate the quantity of cement: Volume of cement = 1/7 × 1.54 = 0.22 m3, cement quantity in kg = 0.22 × 1440 = 317 kg, cement quantity in bags = 317/25 = approx 13 bags.
- Estimate the quantity of sand: Volume of sand = 2/7 × 1.54 = 0.44 m3, sand quantity in kg = 0.44 × 1600 = approx 704 kg, sand quantity in bags = 704/25 = approx 28 x 25kg bags (or 0.7 tonnes).
- Estimate the quantity of aggregate: Volume of aggregate = 4/7 × 1.54 = 0.88 m3, aggregate quantity in kg = 0.88 × 1500 = approx 1320 kg, aggregate quantity in bags = 1320/25 = approx 53 x 25kg bags (or 1.32 tonnes).

Typically, for domestic use, to make 1m3 of concrete with a mix ratio of 1:2:4 you will need to mix approximately 13 x 25 kg bags of cement as well as 704 kilograms (or 28 x 25kg bag) of sand and 1320 kg (or 53 x 25kg bag) of aggregate.

**Here’s how you can calculate quantity of sand, cement and aggregate to make 1 m3 of concrete at 1:3:6 mix:**

- Determine proportion of cement, sand and aggregate: Since the mix ratio is 1 part cement mixed with 3 parts sand and 6 parts aggregate, so total proportion = 1 + 3 + 6 = 10, thus parts of cement = 1/10, parts of sand = 3/10, and parts of aggregate = 6/10.
- Estimate the quantity of cement: Volume of cement = 1/10 × 1.54 = 0.154 m3, cement quantity in kg = 0.154 × 1440 = 222 kg, cement quantity in bags = 222/25 = approx 9 bags.
- Estimate the quantity of sand: Volume of sand = 3/10 × 1.54 = 0.462 m3, sand quantity in kg = 0.462 × 1600 = approx 740 kg, sand quantity in bags = 740/25 = approx 30 x 25kg bags (or 0.74 tonnes).
- Estimate the quantity of aggregate: Volume of aggregate = 6/10 × 1.54 = 0.924 m3, aggregate quantity in kg = 0.924 × 1500 = approx 1386 kg, aggregate quantity in bags = 1386/25 = approx 56 x 25kg bags (or 1.386 tonnes).

Typically, for domestic use, to make 1m3 of concrete with a mix ratio of 1:3:6 you will need to mix approximately 9 x 25 kg bags of cement as well as 740 kilograms (or 30 x 25kg bag) of sand and 1386 kg (or 56 x 25kg bag) of aggregate.

**Here’s how you can calculate quantity of sand, cement and aggregate to make 1 m3 of concrete at 1:4:8 mix:**

- Determine proportion of cement, sand and aggregate: Since the mix ratio is 1 part cement mixed with 4 parts sand and 8 parts aggregate, so total proportion = 1 + 4 + 8 = 13, thus parts of cement = 1/13, parts of sand = 4/13, and parts of aggregate = 8/13.
- Estimate the quantity of cement: Volume of cement = 1/13 × 1.54 = 0.118 m3, cement quantity in kg = 0.118 × 1440 = 170 kg, cement quantity in bags = 170/25 = approx 7 bags.
- Estimate the quantity of sand: Volume of sand = 4/13 × 1.54 = 0.474 m3, sand quantity in kg = 0.474 × 1600 = approx 758 kg, sand quantity in bags = 758/25 = approx 31 x 25kg bags (or 0.758 tonnes).
- Estimate the quantity of aggregate: Volume of aggregate = 8/13 × 1.54 = 0.948 m3, aggregate quantity in kg = 0.948 × 1500 = approx 1422 kg, aggregate quantity in bags = 1422/25 = approx 57 x 25kg bags (or 1.422 tonnes).

Typically, for domestic use, to make 1m3 of concrete with a mix ratio of 1:4:8 you will need to mix approximately 7 x 25 kg bags of cement as well as 758 kilograms (or 31 x 25kg bag) of sand and 1422 kg (or 57 x 25kg bag) of aggregate.

**Here’s how you can calculate quantity of sand, cement and aggregate to make 1 m3 of concrete at 1:2:3 mix:**

- Determine proportion of cement, sand and aggregate: Since the mix ratio is 1 part cement mixed with 2 parts sand and 3 parts aggregate, so total proportion = 1 + 2 + 3 = 6, thus parts of cement = 1/6, parts of sand = 2/6, and parts of aggregate = 3/6.
- Estimate the quantity of cement: Volume of cement = 1/6 × 1.54 = 0.256 m3, cement quantity in kg = 0.256 × 1440 = 370 kg, cement quantity in bags = 370/25 = approx 15 bags.
- Estimate the quantity of sand: Volume of sand = 2/6 × 1.54 = 0.513 m3, sand quantity in kg = 0.513 × 1600 = approx 822 kg, sand quantity in bags = 822/25 = approx 33 x 25kg bags (or 0.822 tonnes).
- Estimate the quantity of aggregate: Volume of aggregate = 3/6 × 1.54 = 0.77 m3, aggregate quantity in kg = 0.77 × 1500 = approx 1155 kg, aggregate quantity in bags = 1155/25 = approx 47 x 25kg bags (or 1.155 tonnes).

Typically, for domestic use, to make 1m3 of concrete with a mix ratio of 1:2:3 you will need to mix approximately 15 x 25 kg bags of cement as well as 822 kilograms (or 33 x 25kg bag) of sand and 1155 kg (or 47 x 25kg bag) of aggregate.

Conclusions:

To make 1m3 of concrete with a mix ratio of 1:2:3, you generally need about 15 bags of 25 kg of cement, while with a mix of 1:2:4, about 13 bags of cement. Likewise, with a mix of 1:3:6, about 9 bags of cement, while with a 1:4:8 mix you will need about 7 bags of 25kg of cement.