Quikrete Calculator
Calculate how many 80-lb bags of Quikrete concrete mix you need using the brand's published 0.60 cu ft yield per bag, plus total cost.
How this calculator works
Quikrete publishes a yield of 0.60 cubic feet per 80-lb bag of its standard concrete mix once water is added. This calculator converts your length, width, and depth into cubic yards, then divides by that 0.60 cu ft figure to get the bag count.
Formula: Cubic yards = (Length ft × Width ft × Depth ft) ÷ 27. Bags = (Cubic yards × 27) ÷ 0.60.
Worked example
A 10 ft × 10 ft slab at a 4-inch depth:
- Depth in feet: 4 ÷ 12 = 0.3333 ft
- Cubic yards: (10 × 10 × 0.3333) ÷ 27 ≈ 1.2346 yd³
- Bags: (1.2346 × 27) ÷ 0.60 ≈ 55.56 bags
- At $7/bag, that’s $388.89 before waste.
Coverage reference
| Slab size | Depth | Quikrete 80-lb bags needed |
|---|---|---|
| 5 ft × 5 ft | 4 in | 13.89 bags |
| 10 ft × 10 ft | 4 in | 55.56 bags |
| 20 ft × 20 ft | 4 in | 222.22 bags |
How to measure your pour
Measure the pour footprint in feet and use the actual finished thickness of the concrete, not any gravel base underneath it. For a post hole, use the hole’s diameter as both length and width to approximate it as a small rectangular volume — this slightly overestimates the bag count, which is the safer direction to round.
Frequently asked questions
Is this an official Quikrete calculator?
No — this is an independent tool built and maintained by ProjectYards, not affiliated with or endorsed by Quikrete Companies, Inc. We use Quikrete's own published yield figures (0.60 cu ft per 80-lb bag) because they're the industry-standard numbers contractors already work from, but the math and the tool are ours.
How much concrete does one 80-lb bag of Quikrete yield?
0.60 cubic feet once mixed with water, per Quikrete's published product data. This calculator converts your project's volume to cubic feet and divides by 0.60 to get the bag count.
What if I'm using Quikrete's 60-lb bags instead of 80-lb?
60-lb bags yield 0.45 cubic feet each — less volume per bag than the 80-lb size, so you'll need more of them. Multiply this calculator's 80-lb bag result by 1.33 to estimate the 60-lb bag count, or just re-run with the smaller yield if you're pricing both options.
Does this work for Quikrete's fast-setting or crack-resistant mixes?
Yes for volume — Quikrete's Fast-Setting and Crack Resistant concrete mixes are also packaged in 80-lb bags with the same 0.60 cu ft yield, so the bag count is identical. Only the cure time and mixing instructions differ between product lines, not the coverage math.
At what pour size should I switch from Quikrete bags to ready-mix?
Once you're approaching roughly 45 bags — about 1 cubic yard — ready-mix delivery from a concrete truck is usually cheaper per yard and far less physical labor. Bagged Quikrete makes the most sense for footings, post holes, and small slabs under that threshold.
How much water does each 80-lb bag need?
Quikrete's packaging calls for about 3 quarts (0.75 gallons) of clean water per 80-lb bag, mixed until the material is workable but not soupy. Adding more water than that weakens the cured strength, so measure it rather than eyeballing it.
Estimates only. Verify quantities with your supplier before purchasing.