Concrete bag calculator
Convert a concrete volume into a bag count using the mixed yield stated for your chosen pre-mixed product.
Result
Bags required
How to use this tool
- Work out your required volume first — use the concrete volume calculator if you don't already know it.
- Enter that volume and the yield per bag printed on the product; the default is only an illustrative starting point.
- Read the number of bags to buy.
Assumptions
- Bag weight does not determine concrete volume exactly. Product mix and stated yield determine how much mixed concrete each bag produces; replace this assumed yield with the packaging/manufacturer figure when available.
- No separate spillage allowance is included.
Technical details: what the fields mean
- Concrete volume needed
volumeM3 - Total concrete volume required, in cubic metres.
- Yield per bag (check the pack)
yieldM3PerBag - Volume of mixed concrete produced by one bag. The 0.0125m³ default is illustrative; replace it with the yield stated on your chosen product's packaging or manufacturer data.
Methodology
Bag count = required volume ÷ yield per bag, rounded up. The editable 0.0125m³ default is illustrative, not exact volume mathematics: actual yield depends on the mix. Use the yield stated on the selected product's packaging or manufacturer data.
Worked example
1m³ of concrete at the illustrative 0.0125m³ mixed yield per bag
Inputs: Concrete volume needed: 1 m³, Yield per bag (check the pack): 0.0125 m³
Result: 80 bags required
Practical guidance
- For volumes above roughly 1m³, ready-mix delivery is usually cheaper and far less labour than mixing dozens of bags by hand.
- Buy a couple of spare bags — running short mid-pour means a hard-to-hide cold joint.
Common mistakes
- Using a generic yield figure without checking the actual bag — yields vary by brand and mix.
- Not rounding up to a whole bag.
FAQs
How many bags of concrete are in a cubic metre?
At the illustrative 0.0125m³ yield per bag, the estimate is 80 bags. Check and enter the yield on your chosen mix's packaging or manufacturer data; it may differ.
Is it cheaper to use bags or ready-mix?
For small jobs (under about 1m³) bags are usually more practical. Above that, a ready-mix lorry is typically better value and less labour.
Last reviewed: 2026-10-11
Yield varies by manufacturer and mix design — treat this as a planning estimate and check your product's packaging.
This tool provides an indicative estimate, based on the assumptions stated above.
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