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Concrete Mix Ratio Calculator

Calculate the cement, sand, and gravel proportions needed for a hand-mixed concrete batch by volume.

Result

Cement
1.67 cu ft
Sand
3.33 cu ft
Gravel
5 cu ft

Ratios are by volume of dry materials before mixing with water - actual mixed concrete volume is somewhat less than the sum of dry ingredient volumes due to how particles settle and fill gaps between each other during mixing.

About the Concrete Mix Ratio

The Concrete Mix Ratio Calculator breaks a target volume of concrete down into the cement, sand, and gravel quantities needed for a hand-mixed batch, based on a chosen mix ratio. It is built for small DIY pours, like fence post footings or a short walkway section, where mixing from bagged materials rather than ordering ready-mix makes sense.

How It Works

You enter the total volume of concrete you need and pick a mix ratio, cement to sand to gravel, from three presets ranging from a standard 1:2:4 mix to a higher-strength 1:1.5:3 mix. The calculator adds up the ratio's parts, then divides your total volume proportionally across cement, sand, and gravel according to each material's share of those parts.

Total parts = cement ratio + sand ratio + gravel ratio, from the chosen ratio such as 1:2:3. Cement volume = total volume x cement ratio / total parts. Sand volume = total volume x sand ratio / total parts. Gravel volume = total volume x gravel ratio / total parts.

Examples

Standard 10 Cubic Foot Batch

At the default 1:2:3 ratio, 6 total parts, a 10 cu ft batch needs about 1.67 cu ft of cement, 3.33 cu ft of sand, and 5.00 cu ft of gravel.

High-Strength 15 Cubic Foot Batch

Using the 1:1.5:3 high-strength ratio, 5.5 total parts, for a 15 cu ft batch needs about 2.73 cu ft of cement, 4.09 cu ft of sand, and 8.18 cu ft of gravel.

Advantages

  • Turns a mix ratio, which is easy to misjudge by eye, into exact proportional volumes for each material.
  • Lets you compare how switching between the three preset ratios changes the cement, sand, and gravel split for the same total volume.
  • Useful for converting a bag-mix recipe into consistent batch sizes when hand-mixing multiple batches for one project.

Common Mistakes

  • Buying materials based on the exact calculated dry volumes without extra margin, when actual mixed concrete yield runs lower than the sum of dry component volumes.
  • Mixing ratio components by weight instead of by volume, when these ratios, like 1:2:3, are meant to be measured by volume, such as with a shovel or bucket.
  • Choosing a higher-strength ratio for a project that does not need it, adding unnecessary cement cost when a standard mix would meet the load requirements.

Edge Cases to Watch For

  • The ratio is only selectable from three fixed presets, 1:2:3, 1:2:4, and 1:1.5:3, so it does not accept a custom ratio typed in directly.
  • Results are dry, pre-mix volumes of each material; mixed concrete volume ends up somewhat less than the sum of these dry volumes because particles settle and fill the gaps between each other during mixing, so buying exactly the calculated amounts leaves little margin.
  • A higher-strength ratio like 1:1.5:3 shifts more of the total volume toward cement relative to a standard 1:2:4 mix, which changes both material cost and cured strength, not just the proportions.

Common Use Cases

  • DIYers hand-mixing concrete in a wheelbarrow or mixer for small footings, posts, or slabs.
  • Anyone comparing material costs between a standard and a high-strength mix ratio before buying bagged cement, sand, and gravel.
  • Builders converting a specified mix ratio into batch-by-batch material amounts for a multi-batch pour.
Written & fact-checked by the Calculateus TeamLast updated August 5, 2026How we verify our formulas

Frequently asked questions

Why does a higher-strength mix use relatively more cement?

Cement is the binding agent that holds sand and gravel together and provides compressive strength as it cures, so mixes with a higher proportion of cement relative to aggregate (like 1:1.5:3 versus 1:2:4) generally cure to higher strength, though also cost more per batch since cement is the most expensive component by volume.

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Conclusion

This calculator turns a cement-to-sand-to-gravel ratio into concrete batch volumes you can measure out by bucket or shovel. Because it works from dry-material presets, it is best suited to small hand-mixed pours rather than specifying a delivered ready-mix truck order.