For a concrete slab, you can mix bagged concrete on site or order ready-mix concrete delivered by truck. Both end up as concrete, but they differ in batching, timing, and waste. This guide compares the two, with sizing help from the Concrete Slab Calculator, the Concrete Mix Calculator, and the Concrete Slab Cost Calculator.
Bagged vs ready-mix concrete comparison
| Feature | Bagged concrete | Ready-mix concrete |
|---|---|---|
| Supply form | Dry bags mixed with water on site | Wet concrete batched at a plant and delivered |
| Batch size | Small batches, bag by bag | Large continuous loads by the truck |
| Timing | Mixed when needed, in stages | Must be placed within the delivery window |
| Consistency | Depends on on-site mixing and water | Batched to a set mix at the plant |
| Equipment | Mixer, wheelbarrow, and water on site | Truck access and placing equipment |
| Waste | Unused bags can often be kept dry for later | Ordered volume must match the slab closely |
| Best checked with | Concrete Mix Calculator | Concrete Slab Calculator |
Lifespan and maintenance comparison
Once cured, the slab itself is the same kind of material either way, so lifespan and maintenance depend mainly on mix, thickness, reinforcement, curing, drainage, and loads — not on whether the concrete arrived in bags or by truck. Poor curing, too much water in the mix, or a weak base will shorten the life of either supply. Keep the slab drained, seal joints where specified, and repair cracks promptly.
Choose bagged if / choose ready-mix if
Choose bagged if:
- Your slab is small, remote, or hard for a truck to reach.
- You want to work in stages or spread the job over several sessions.
- You can mix consistently and allow for the extra labor.
Choose ready-mix if:
- Your slab is large enough for a continuous pour.
- You want plant-batched consistency and a faster placement.
- Truck access and timing can be arranged for the pour.
Worked example (illustrative only)
This example is illustrative only; it is not a quote. Take a slab 12 feet by 10 feet at 4 inches thick. Volume is 12 × 10 × (4 ÷ 12) = 40 cubic feet, which is 40 ÷ 27 = 1.48 cubic yards. With a 10% waste allowance, the order volume is 40 × 1.10 = 44 cubic feet, or 1.63 cubic yards. For bagged concrete, 44 ÷ 0.60 = 73.33, so 74 bags of 80 lb are needed. For ready-mix, order 1.63 cubic yards. At illustrative rates, bagged concrete at $5 to $7 per bag gives 74 × $5 = $370 to 74 × $7 = $518, while ready-mix at $150 to $200 per cubic yard gives 1.63 × $150 = $244.50 to 1.63 × $200 = $326, before any delivery charge. Check your own slab with the Concrete Slab Calculator and the Concrete Mix Calculator.
Frequently asked questions
Is bagged or ready-mix concrete stronger?
Strength depends on the mix, water content, placing, and curing, not on the supply form alone. Follow the mix and curing instructions for the supply you choose.
How many bags do I need for a slab?
Work out the slab volume in cubic feet, add a waste allowance, then divide by the coverage per bag. The Concrete Slab Calculator does this for 80 lb and 60 lb bags.
When is ready-mix the better choice?
Ready-mix suits larger, continuous pours where truck access and timing work. Bagged concrete suits smaller or staged jobs where a truck is impractical.
Method note
This is a planning guide, not a specification. Figures in the worked example are illustrative only, except for the volume and bag arithmetic shown. Confirm mix, thickness, reinforcement, curing, and local requirements with your supplier before ordering.