Concrete Mix Ratio Calculator
Calculate how much cement, sand and aggregate you need for a concrete volume at any mix ratio (1:2:4, 1:1.5:3, custom) — in bags, kg and cubic meters.
Input
Finished (wet) volume of concrete you need.
Extra material for spillage and uneven surfaces.
Dry materials occupy about 1.54x the wet volume (1.52–1.57 is typical).
Output
| Material | Volume (m³) | Weight (kg) | Notes |
|---|---|---|---|
| No data yet | |||
More ways to use this tool
REST API
curl -X POST https://api.iotools.cloud/v1/tool/concrete-mix-ratio-calculator \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"volume": "1",
"unit": "m3",
"ratio": "1:2:4",
"wastage": "0",
"dryFactor": "1.54"
}'Swap in your own key from your account. The tool's fields are the body — no wrapper.
Ask an AI agent
Use the IOTools `concrete-mix-ratio-calculator` tool (Concrete Mix Ratio Calculator) on this input:
YOUR_INPUT_HEREPaste this at any agent connected to the IOTools MCP server, then add your input.
Embed widget
<iframe
src="https://iotools.cloud/embed/concrete-mix-ratio-calculator/"
width="100%" height="520" frameborder="0" scrolling="no" loading="lazy"
title="Concrete Mix Ratio Calculator — iotools.cloud"
sandbox="allow-scripts allow-forms allow-same-origin allow-downloads allow-popups allow-popups-to-escape-sandbox"
allow="clipboard-write"
style="width:100%;border:1px solid #e5e7eb;border-radius:12px;overflow:hidden"></iframe>
<script src="https://iotools.cloud/embed.js" async></script>Drop this into your own page — free, no key required, just a link back.
| Cost per API/MCP call | From 5 credits |
|---|---|
| Need more credits? | View pricing |
Also available with
Guides
Work out how much cement, sand and coarse aggregate to order for a pour. Enter the finished concrete volume, pick a standard mix ratio (or type your own cement : sand : aggregate parts) and get quantities in bags, kilograms and cubic meters.
How it works
Wet concrete is denser than the loose materials that go into it, so the dry volume is larger than the volume you pour. The calculator multiplies your volume by a dry factor (1.54 by default), adds your wastage allowance, then splits the dry volume by the ratio parts. Weights use typical bulk densities: cement 1,440 kg/m³, sand 1,600 kg/m³, aggregate 1,500 kg/m³. Cement bags are 50 kg.
Common mix ratios
- 1:1:2 (M25) — high-strength work.
- 1:1.5:3 (M20) — beams, columns and slabs.
- 1:2:4 (M15) — footings, floors and general work.
- 1:3:6 (M10) — lean concrete and blinding layers.
All calculations run in your browser — nothing is uploaded.
Does this include water?
No. Water is added by water–cement ratio (commonly 0.4–0.6 by weight of cement) and depends on the mix design and workability you need.
These are estimates
Bulk densities vary with moisture and source. Check your supplier's figures and the structural specification before ordering.