Concrete Mix Calculator
Find how much cement, sand, gravel and water a site-mixed batch of concrete needs for a given mix ratio, from a volume or dimensions.
Change the values and press Calculate to work out your own figures.
From a volume
Enter the volume of concrete and choose the mix.
Show the working
- dry volume = wet volume × 1.54
- each part = dry volume × part ÷ 16
- one 94 lb bag of cement ≈ 1 cu ft
- water = cement weight × 0.6
From dimensions
Enter the length, width and depth and choose the mix.
Show the working
- dry volume = wet volume × 1.54
- each part = dry volume × part ÷ 7
- one 94 lb bag of cement ≈ 1 cu ft
- water = cement weight × 0.5
How to use it
Enter the volume of concrete and choose the mix. Enter the length, width and depth and choose the mix.
Lengths can be decimals, fractions or tape entries such as 12' 6 1/2" (in feet or inches). Prices are optional.
Key facts
dry volume = wet volume × 1.54 each part = dry volume × its share of the ratio cement bags = cement cubic feet (one 94 lb bag ≈ 1 cu ft) water = cement weight × water–cement ratio
Nominal mixes
Volume mixes are for small, non-structural pours. Structural concrete is specified by strength and batched by weight; ask a ready-mix supplier.
Questions
How much cement for a cubic yard of 1:2:4 concrete?
6 bags of 94 lb (5.94 cu ft).
Why multiply by 1.54?
Dry materials shrink by about a third when mixed with water, as the fine particles fill the gaps.
Formulas
dry volume = wet volume × 1.54 each part = dry volume × its share of the ratio cement bags = cement cubic feet (one 94 lb bag ≈ 1 cu ft) water = cement weight × water–cement ratio
Sources
Limitations
- Material densities are typical values (the midpoint of the commonly published range); real loads vary with moisture, grading and compaction, so check with your supplier or type in their density.
- Tank results are the geometric volume; real tanks have wall thickness and fittings.