Proper calculation and proportioning are very important for good quality work. When, we will estimate and proper planning before the final works, and we can reduce the cost & time. So, this article will explain to you the easy techniques, how to calculate Cement, Sand and Aggregate Quantity in concrete.

Concept of Cement, Sand and Aggregate in Concrete

Cement, Sand and Coarse Aggregate are available in the concrete mix. The concrete proportion, concrete strength and concrete grades decide will be based on the structure.

Ordinary concrete is classified into different grades like M5, M7.5, M10, M15, M20 and M25 etc, based on strength.

Grades of Concrete	Ratio C:S:A	Compressive Strength (MPa)
M25	1:1:2	25MPa
M20	1:1.5:3	20MPa
M15	1:2:4	15MPa
M10	1:3:6	10MPa
M7.5	1:4:8	7.5MPa
M5	1:5:10	5MPa

How to Calculate Concrete Volume?

To accurately calculate a total concrete volume by using a tape measure, notepad, pen and a calculator. Firstly, using the tape and measure length, wide & depth in your concrete area.

Rectangular Shape, Circle Column Shaped, Triangular Shape etc.

Rectangular Shape

Figure 1: The formula of Rectangular Shape, Volume (V) = Length (L) × Height (H) × Depth (D)

If, L= 3 feet, H= 2 feet and D= 6 Inch

∴ Volume (V) = L×H×D Cubic
V= 3 feet×2feet×6inch
V= 36 inch × 24 inch × 6 inch [∵ 1feet=12inch]
V= 5184 cubic inch
V= 3 cubic feet (cft) [∵ 1cft=(12×12×12) or 1728 cubic inch]

Circle Column Shaped

Figure 2: The formula of Circle Column Shape, Volume (V) = Height (H)×πR^2 [π(pi)=3.1416, R^2= Radius Square]

If, L= 4 feet, R= 2feet

∴ Volume (V) = L×πR^2 Cubic
V= 4×π×(2^2) cubic feet
V= 4×3.1416×4 cft
V= 50.27 cft

Triangular Shape

Figure 3: The formula of Triangular Shape, Volume (V) = Height (H)×√{s(s-a)(s-b)(s-c)}

If, H= 4 feet, a=11feet, b=6feet, c=7feet

∴ S=(a+b+c)÷2 =>(11+6+7)÷2 =>24÷2 =>12

∴ Volume (V) = H×√{s(s-a)(s-b)(s-c)} Cubic
V= 4×√{12(12-11)(12-6)(12-7)} cubic feet
V= 4×√(12×1×6×5) cft
V= 4×√(360) cft
V= 4×18.97 cft
V= 75.89 cft

Quantity of Cement, Sand And Aggregate

How much cement, sand and aggregate to need in your concrete works, you’ll calculate now. I will explain easily calculate on grade of concrete m20 and m10 in bellow.

How to Calculate Cement, Sand and Aggregate Quantity in M20 Concrete

If, Concrete Volume is 75.89 cft

We know, dry Volume 54% addition of wet Volume.

In other words,
Total dry concrete Volume= 75.89+54% cft
=75.89+(75.89×0.54) cft
=75.89+40.98 cft
=116.87cft
≈117cft

Sum Of Cement, Sand and Aggregate Ratio
=1:1.5:3
=1+1.5+3
=5.5

Bags of Cement

Cement= [(Cement Ratio × Quantity of Dry Volume) ÷ Sum of Rato] cft
=(1×117)÷5.5 cft
=117÷5.5 cft
=22.27 cft
=22.27÷1.25 bags [50kg 1bag cement = 1.25 cft, cement]
=17.82 bags
≈18 bags cement

Quantity of Sand

Sand= [(Sand Ratio × Quantity of Dry Volume) ÷ Sum of Rato] cft
=(1.5×117)÷5.5 cft
=175.5÷5.5 cft
=31.91 cft

Quantity of Coarse Aggregate

Aggregate= [(Aggregate Ratio × Quantity of Dry Volume) ÷ Sum of Rato] cft
=(3×117)÷5.5 cft
=351÷5.5 cft
=63.82 cft