Concrete Mix Calculator

Calculate volumes, mix ratios, bag counts and material quantities for concrete projects. Live preview and downloadable PDF report.

Dimensions & Settings
Waste Factor 10%
Typical retail price
Delivered price per yard
Live Preview
Calculation Results
Enter dimensions above to see results
—
cubic yards
Awaiting input
Fill in the dimensions to calculate
01
Select shape
Choose slab, column, footing, or post holes using the tabs.
02
Enter dimensions
The preview updates instantly as you type, confirming your inputs.
03
Choose mix grade
Pick M5–M25 to match your project. Higher grades = stronger concrete.
04
Review & export
See material breakdown and download the branded PDF report.
Recommended mix grades by application
GradePSIRatio (C:S:A)Best for
M57251:5:10Leveling, non-structural fill
M1014501:3:6PCC work, walkways
M1521751:2:4Footings, light structural
M2029001:1.5:3Slabs, driveways, general RCC
M2536251:1:2Columns, beams, bridges
Volume formulas
Slab: V = L × W × T
Column / round: V = π × (D/2)² × H
Footing / wall: V = L × W × D
Post holes: V = π × (D/2)² × H × Qty

Dry volume adjustment
Concrete compacts during curing — dry mix volume is larger:
Dry Volume = Wet Volume × 1.54

Mix proportioning (M20 example, ratio 1 : 1.5 : 3, total parts = 5.5)
Cement = (1 / 5.5) × Dry Volume
Sand = (1.5 / 5.5) × Dry Volume
Aggregate = (3 / 5.5) × Dry Volume

Cement bags
Cement mass = Cement Volume × 1440 kg/m³
50 kg Bags = Cement mass ÷ 50

Water (w/c ratio = 0.45)
Water = Cement mass × 0.45 (litres = kg)

Waste factor
Final Volume = Calculated Volume × (1 + waste%)