About Concrete Pour Calculator

Concrete Pour Calculator is a free set of concrete calculators built for the way concrete actually gets bought: by the bag, by the yard, and by the Saturday.

Why this site exists

Ordering concrete is a one-way door. Order too little and a truck cannot send back a shortage — you get a cold joint, a weakened slab, or an emergency bag run with wet concrete waiting. Order too much and you have paid to have the extra hauled away. The math is not hard, but it is unforgiving, and the numbers people actually need — bags by size, yards with a real waste allowance, bags vs. a truck with real prices — are usually scattered across five different pages.

So we built one place that does the whole calculation honestly: manufacturer-published bag yields, both the exact volume and the order volume, and a cost comparison where every price is an editable input with a labeled national-average default — never a fake "quote."

How the numbers work

• Bag yields are the standards published by the major bagged-mix manufacturers: an 80 lb bag yields 0.60 cu ft, 60 lb yields 0.45, 50 lb yields 0.375, and 40 lb yields 0.30.
• Volumes are school geometry, double-checked: rectangles, cylinders for post holes, and the stepped formula for stairs.
• Waste allowance defaults to 10% — the standard pros order by — and you can change it to 5% or 15%.
• Prices are planning averages you can edit. Your local supplier's real numbers will always beat our defaults.

Part of a small family of free tools

Concrete Pour Calculator is published by The Agency LLC as part of a small family of free calculator sites. The calculators run entirely in your browser — read our privacy page for exactly what that means (short version: your project numbers are never sent anywhere or saved).

Found an error?

We would rather fix it than be confidently wrong. See the contact page for how to reach the publisher.