Ready-mix vs bagged concrete: which should you use?
Last reviewed 1 July 2026
Short answer
Bagged concrete wins below about 0.25 m³ (a third of a cubic yard) because there is no delivery minimum. Ready-mix wins above about 1 m³ on both cost and effort. Between the two it depends on your local delivery charges, whether you can get a truck to the pour, and how many people you have.
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The effort nobody costs in
A cubic metre of concrete needs about 85 bags of 25 kg ready-to-use mix. That is 2.1 tonnes to unload, carry, open, tip into a mixer, mix, and barrow to the pour — and each mixer load is a small fraction of the total.
A 130-litre mixer produces roughly 0.08 m³ of concrete per batch. A cubic metre is around 13 batches. Allowing five minutes per batch including loading and discharging, that is over an hour of continuous mixing before you count barrowing and placing.
The same cubic metre arrives in a ready-mix truck in one delivery and discharges in minutes.
| Volume | 25 kg bags | Total bag weight | Approx. mixer batches |
|---|---|---|---|
| 0.1 m³ | 9 | 225 kg | 1–2 |
| 0.25 m³ | 22 | 550 kg | 3 |
| 0.5 m³ | 43 | 1,075 kg | 6 |
| 1.0 m³ | 85 | 2,125 kg | 13 |
| 2.0 m³ | 170 | 4,250 kg | 25 |
Bag counts use a yield of about 0.0118 m³ per 25 kg bag.
Where each one wins
| Factor | Bagged | Ready-mix |
|---|---|---|
| Very small volumes | Clear winner — no minimum | Short-load fees apply |
| Cost per cubic metre | Highest | Lowest |
| Access | Anywhere you can carry a bag | Truck needs to reach within chute range |
| Timing | Work at your own pace | Fixed discharge window |
| Consistency | Varies batch to batch | Batched to specification |
| Cold joints | Real risk on anything sizeable | Avoided — one continuous pour |
| Storage | Bags keep, if kept dry | Nothing to store |
Getting ready-mix right
- Be ready before it arrives. Formwork braced, reinforcement placed on spacers, tools out, and enough people to place and finish.
- Ask about the discharge window. Most suppliers allow a set time on site and charge waiting time beyond it.
- Check access. A truck needs firm ground, headroom and enough width. A chute reaches only a few metres; beyond that you need a pump or a lot of barrows.
- Specify properly. Tell the plant what the concrete is for so they supply the right strength class and workability, and mention if you want a retarder for a long pour.
- Have somewhere to wash out. Truck washout has to go somewhere that is not a drain.
Important: Concrete does not wait
The middle ground
Between about 0.25 m³ and 1 m³, look at two other options. Volumetric mixers batch on site and only charge for what you use, which removes the over-order risk and the minimum load problem. Some suppliers also offer 'mix on site' trailers for small quantities.
If you go bagged at this scale, hire the biggest mixer you can and organise a production line: one person loading, one mixing, one barrowing, one placing. Doing it alone is what turns a half-day job into a weekend.
Safety notice: Material planning only