Published August 12, 2026 · Updated August 23, 2026 · By Tupep
The question behind the question
Nobody actually wants to know whether bags or ready-mix is cheaper in the abstract. They want to know whether this pour, at this size, on this weekend, is worth a pallet of bags or a phone call to the batch plant. The honest answer is that the crossover is not a fixed number of yards. It moves with one variable most people never write down, which is the fixed fee the plant charges you no matter how little concrete you order.
When we worked the crossover out on paper rather than trusting the figure everyone repeats, the answer moved depending on one thing nobody mentions: whether you are paying a short-load fee. Below the truck’s minimum, ready-mix carries a surcharge that can double the effective yard price, and that pushes the break-even higher than the bare arithmetic suggests. We have set the comparison below to show both, so you can see where your own supplier lands.
The three costs that decide it
- Bag cost per yard. Forty five 80 lb bags per cubic yard, plus waste, times your local bag price. This scales linearly. Two yards costs exactly twice what one yard costs.
- Ready-mix cost per yard. Also linear, and always cheaper per yard than bags. Concrete in a truck is the cheapest concrete there is.
- Fixed fees. Short load charges, delivery or fuel surcharges, and Saturday fees. These do not scale. They are the entire reason small pours favor bags.
Most plants have a minimum load, commonly in the 1 to 5 yard range depending on the market, and charge a short load fee per yard under it. That fee is what you are really buying your way past when you scale a job up.
The break-even formula
Set the two totals equal and solve. Let B be your delivered bag cost per cubic yard including waste, R the ready-mix price per cubic yard, and F the total fixed fees on a small delivery.
Break-even yards = F / (B – R)
That is the whole thing. Below that volume, bags win. Above it, the truck wins and keeps winning by a widening margin.
Worked example with real-shaped numbers
Use your own local prices, these are placeholders to show the arithmetic. Say 80 lb bags are $6.50 each, ready-mix is $180 per yard, the short load fee is $150, and delivery is $40.
Bag cost per yard: 45 bags x 1.10 waste = 49.5 bags, times $6.50, which is $321.75 per yard. Fixed fees total $190.
Break-even = 190 / (321.75 – 180) = 190 / 141.75 = 1.34 cubic yards.
Check it. At 1.34 yards, bags cost 1.34 x 321.75 = $431. Ready-mix costs 1.34 x 180 + 190 = $431. They match. Under about 1.3 yards, which covers most patios, pads, and post jobs, bags are cheaper. Over it, the truck pulls ahead fast.
| Volume | 80 lb bags (+10%) | Bag cost | Ready-mix cost | Cheaper option |
|---|---|---|---|---|
| 0.25 cu yd | 13 | $84.50 | $235 | Bags, by a lot |
| 0.5 cu yd | 25 | $162.50 | $280 | Bags |
| 1.0 cu yd | 50 | $325.00 | $370 | Bags, narrowly |
| 1.5 cu yd | 75 | $487.50 | $460 | Ready-mix, narrowly |
| 2.0 cu yd | 99 | $643.50 | $550 | Ready-mix |
| 3.0 cu yd | 149 | $968.50 | $730 | Ready-mix |
| 5.0 cu yd | 248 | $1,612.00 | $940 | Ready-mix, no contest |
Money is not the binding constraint. Time is.
The table above is only half the decision, and in our experience it is the less important half. Concrete does not wait for you.
At around 70 degrees, ordinary bagged mix begins its initial set within roughly an hour or two of hitting water, and a hot, dry, windy day cuts that down sharply. Every batch you place has to go against concrete that is still plastic. If it does not, you get a cold joint, which is a permanent plane of weakness and usually a visible line in the finish.
Now count batches. A typical rental mixer takes two or three 80 lb bags per batch. Loading, mixing, dumping, and moving is a few minutes per batch, so a two person crew moving steadily places somewhere around 20 to 25 bags an hour once you account for hauling bags and screeding behind yourself. That means 45 bags, one single cubic yard, is roughly a two hour continuous pour with no breaks. Ninety bags is a genuinely hard day and a real cold joint risk.
Our rule is simpler than the cost math. One yard is a comfortable bag job for two people. Two yards is possible and unpleasant. Three yards should be a truck regardless of what the spreadsheet says.
The option in the middle
Volumetric or short load trailers mix on site and meter what you actually use, so you pay for 1.75 yards instead of buying 2 and eating the rest. They fill the awkward 1 to 3 yard gap where bags are miserable and a full truck is wasteful. Availability varies a lot by market, so call around before you assume it is an option.
Details that shift the answer
- Access. If the truck cannot reach the pour, you are wheelbarrowing anyway, and a 10 yard truck emptied by barrow is a nightmare. Free unload time is commonly a handful of minutes per yard before per minute charges start.
- Finish quality. Truck concrete is batched to a consistent mix design. Hand mixed bags vary batch to batch, which shows up as color variation on a broom finish.
- Bag condition. Bags that have sat in a damp shed develop hard lumps. That cement is already partly hydrated and will not gain full strength. Squeeze a few bags before you buy a pallet.
- Slump discipline. Soupy concrete is easier to place and weaker in every way. Adding water past the mix design cuts strength and drives shrinkage cracking, whether it comes from your hose or the driver’s.
Related guides
- How Much Concrete Per Fence Post
- Gravel Base Depth Under a Paver Patio
- How Many Bags of Concrete for a 10×12 Shed Slab
- How Many Tons of Gravel for a 20×40 Driveway
Sources and Further Reading
Run your own numbers with the Concrete Slab Calculator, or browse every tool on the calculators index. Coverage figures and material constants are cross-checked against manufacturer technical data sheets before publication. See our Methodology page for how figures are selected and verified.
Planning estimate only. Results assume standard conditions and are intended for material planning. Verify against your product’s technical data sheet and your local building code before purchasing. Structural, electrical, and gas work should be specified by a licensed professional.
Last updated: August 23, 2026
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