Concrete Calculator

Calculate exact quantities of cement, sand, and aggregate for construction projects Imperial Units

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Input Parameters

Select Structural Element:

Beam Lengthft /m

Typical: 8-20 ft

Beam Widthin /mm

Typical: 9-12 in

Beam Depthin /mm

Typical: 12-24 in

Number of Beams

Concrete Mix Settings

M20

1:1.5:3

M15

1:2:4

M25

1:1:2

M30

1:0.75:1.5

Water-Cement Ratio

Typical: 0.45 for M20

Construction Wastage

Wastage Percentage: 4%

0% (Minimal)5%10% (High)

Recommended: 4% for concrete work (includes spillage, uneven surfaces, over-excavation)

Calculation Results

Wet Concrete Volume

0.00 ft³

0.00 m³

Dry Concrete Volume

0.00 ft³

0.00 m³

Material Quantities

Cement

bags (50 kg each)

Sand

0.00

ft³

Aggregate

0.00

ft³

Water

liters

Volume Breakdown

Element Volume:0.00 ft³

Number of Elements:1

Total Volume:0.00 ft³

Wastage Added:0.00 ft³

Mix Ratio Details

Material	Ratio	Quantity
Cement	1 part	0 bags
Sand	1.5 parts	0 ft³
Aggregate	3 parts	0 ft³
Water	0.45 w/c	0 liters

Concrete Mix Standards

M15 (1:2:4): General purpose, non-structural concrete

M20 (1:1.5:3): Reinforced concrete, structural work

M25 (1:1:2): High strength concrete, columns, beams

M30 (1:0.75:1.5): Heavy duty, industrial floors

Concrete Calculation Standards

Volume Calculation

Wet Volume Formula:

Volume = Length × Width × Depth

Dry Volume Conversion:

Dry Volume = Wet Volume × 1.54
Factor 1.54 accounts for voids in dry materials
Concrete shrinks after mixing and placement

Wastage Factor: Typically 4-5% for spillage and uneven surfaces

Material Proportions

Mix Ratio (Cement:Sand:Aggregate):

Grade	Ratio	Use Case
M15	1:2:4	Flooring, PCC
M20	1:1.5:3	RCC beams, slabs
M25	1:1:2	Columns, foundations
M30	1:0.75:1.5	Industrial floors

Water-Cement Ratio: Critical for strength - typically 0.45 for M20

Material Densities

Cement: 1440 kg/m³ (90 lb/ft³)
Sand (dry): 1600 kg/m³ (100 lb/ft³)
Aggregate: 1500 kg/m³ (93.6 lb/ft³)
Fresh Concrete: 2400 kg/m³ (150 lb/ft³)

Cement Bag Standards:

1 bag cement = 50 kg = 1.25 ft³
1 bag cement = 0.0347 m³
Yield: ~0.134 m³ concrete per bag (M20 mix)

Note: Always order 5-10% extra material for contingencies