How to use it
- Enter diameter (in), depth (ft), and quantity.
- Click Calculate.
- Read the cubic‑feet total, then see the equivalent bags and cubic‑yard amount.
This tool turns the size and count of your post holes into three practical measures: total cubic feet, how many 80‑lb bags of mix you’ll need, and the volume in cubic yards. Knowing the cubic‑foot total lets you verify the amount of mix you’ll pour, while the bag count helps you order the right quantity without over‑buying. The cubic‑yard figure is useful for larger projects or when ordering bulk material. Results appear instantly, so you can adjust hole dimensions or quantity on the fly and see how each change impacts material needs. No guesswork—just clear numbers you can act on.
Pro tips
- Add 5‑10% extra for spillage and settling when ordering bags.
- Round up bag count to the next whole bag; you can’t buy a fraction of a bag.
- If you need a large volume, ask the supplier for bulk pricing by the cubic yard.
- Double‑check that diameter is entered in inches and depth in feet to avoid unit errors.
Real-life examples
- A homeowner planning a new fence needs to know how much concrete to buy for 20 4‑inch‑diameter, 3‑ft‑deep post holes.
- A contractor estimating material for a deck’s support posts wants quick bag counts for multiple hole sizes.
- A landscaper ordering bulk concrete for a row of garden stakes wants the total cubic‑yard amount for delivery.
Case study
Mike entered 12 holes at 4" diameter and 2 ft depth; the calculator showed 1.75 ft³, about 3 × 80‑lb bags (0.06 yd³). He ordered three bags, avoided a costly over‑order, and completed his fence on schedule.