How to use it
- Enter length in feet
- Enter width in feet
- Enter thickness in inches
- Read cubic feet, cubic yards, and bag count results
The Footing Calculator converts the dimensions of a concrete footing into three useful measures: cubic feet, cubic yards, and the number of 80‑lb bags needed. Knowing the exact volume helps you order the right amount of mix, avoid costly over‑orders, and keep your project on schedule. You enter length and width in feet and thickness in inches; the tool first turns thickness into feet, multiplies length × width × thickness to get cubic feet, divides by 27 for cubic yards, and divides cubic feet by 0.6 to estimate bags. For example, a 10 ft × 5 ft footing that is 6 in thick equals 25 ft³, about 0.93 yd³, and requires roughly 42 bags. Add a 5‑10% contingency to cover spillage and compaction. The calculator updates instantly as you tweak dimensions, so you can experiment with different footing sizes without manual math.
Pro tips
- Include a 5‑10% waste factor when ordering bags.
- Round up bag count to the nearest whole bag.
- Order an extra bag for unexpected mix variations.
- Double‑check that thickness is entered in inches, not feet.
Real-life examples
- A homeowner planning a new patio footings.
- A contractor estimating material for a residential foundation.
- A DIY landscaper building a retaining wall base.
Case study
Mike needed a 12 ft × 8 ft footing 8 in thick for his garage. Using the calculator he saw he required 42 ft³ (≈1.6 yd³) and 70 bags, preventing a $300 over‑order.