About BagOrTruck
Every concrete pour starts with the same question: buy bags and mix it yourself, or order a ready-mix truck? BagOrTruck is a free calculator built to answer that question with real math instead of a guess.
Enter the size of your pour and the calculator figures the volume in cubic feet and cubic yards, how many bags of each standard size it takes, and what both routes cost side by side. No sign-up, no email address, nothing to download. BagOrTruck launched in October 2026.
Who It's For
Homeowners and DIYers pricing out a slab, a patio, a shed pad, a walkway, or a run of fence posts. If you are standing in a store aisle trying to decide whether 40 bags is enough, or wondering whether the delivery fee on a small truck order is worth it, this is the tool we built.
How the Numbers Are Computed
Nothing here is a black box. The calculator uses the standard manufacturer yields printed on the bags:
| Bag size | Yield |
|---|---|
| 80 lb bag | 0.60 ft³ |
| 60 lb bag | 0.45 ft³ |
| 50 lb bag | 0.375 ft³ |
| 40 lb bag | 0.30 ft³ |
Volume is length × width × thickness, converted to cubic feet, then to cubic yards by dividing by 27. Bag counts are the volume divided by the yield, always rounded up, because you cannot buy part of a bag and running short mid-pour leaves a weak cold joint.
Two adjustments are built in because they reflect how pours actually work:
- Waste allowance: a 10% default (adjustable in the calculator) for spillage, uneven ground, and forms that are not perfectly level.
- Ready-mix minimums: ready-mix is billed the way suppliers actually bill it, including a minimum load of 1 cubic yard plus delivery, so small pours honestly show why bags often win under a yard.
The guide pages on this site use the same math, and they show the worked arithmetic so you can check any number by hand. See the 10×10 slab guide, the 10×20 slab guide, and the slab cost guide.
About the Prices
The prices in the cost comparison are editable defaults, not quotes. They start at typical figures ($6.50 per 80 lb bag, $160 per cubic yard of ready-mix, $75 delivery) so the comparison works the moment the page loads, but concrete prices vary a lot by region and supplier. Change them to your local store price and an actual quote from a ready-mix company before you make a decision. The bag count and yardage are the same everywhere; the dollars are not.
Estimates Only
Results are planning estimates. Actual concrete needs vary with ground conditions, form accuracy, over-excavation, and product yield. Bag yields follow manufacturer figures for standard mixes; your product may differ slightly. Always order a little extra — running short mid-pour creates a weak cold joint. For structural work (foundations, load-bearing footings, retaining walls), consult a licensed professional and follow your local building code. Our privacy policy explains how this site handles data, advertising, and affiliate links.