Footing Calculator
Concrete for continuous and pad footings, with the order quantity.
Footings
= 480" (40')
= 16" (1' 4")
= 8"
= 24" (2')
= 24" (2')
= 12" (1')
Results update as you typeLive
Footing · Result
CalculatedORDER (INCL. 10% WASTE)
2.25 cubic yards to order
- Net volume
- 1.91 yd³
- With waste
- 2.1 yd³
- Footings
- 2
- Waste
- 10%
Waste allowance 10%
SUGGESTED DEFAULTChangeOutput unit defaulted to cubic yards because at least one dimension was entered in imperial units
SUGGESTED DEFAULTReady-mix order increment 0.25 yd³ and minimum 1 yd³ are UI defaults; suppliers differ
SUGGESTED DEFAULTBag counts use each product's printed approximate yield; cubic-metre yields are derived from the printed cubic-feet figures — see Methodology
MFR SPECCode references & assumptions · 3
How this result is supported
- SUGGESTED DEFAULTOutput unit defaulted to cubic yards because at least one dimension was entered in imperial units
- ASSUMPTION
- SUGGESTED DEFAULTReady-mix order increment 0.25 yd³ and minimum 1 yd³ are UI defaults; suppliers differ
- ASSUMPTION
- MFR SPECBag counts use each product's printed approximate yield; cubic-metre yields are derived from the printed cubic-feet figures — see Methodology
- PRIMARY-VERIFIED
What do these evidence labels mean?
- PRIMARY-VERIFIED
- directly supported by one authoritative primary source, quoted with section/page/figure
- CROSS-VERIFIED
- independently supported by two or more appropriate authoritative sources
- DERIVED
- mathematically derived from PRIMARY-VERIFIED values; the derivation is preserved in data and in code
- INTERPRETED
- a source exists but translating it into calculator behaviour required interpretation
- CONVENTION
- recognised trade practice, not a mandatory provision
- ASSUMPTION
- product/design assumption or useful default with no authoritative basis
- UNVERIFIED
- insufficient authoritative evidence
Code references and product data are quoted in the units their source uses.
Reference checks are informational, not compliance determinations.
How footing is calculated
A continuous footing and a pad footing are the same geometry at different lengths — length × width × depth — so both are entered the same way and a foundation with four pads and two runs is one calculation.
Give each entry a count where they repeat: eight identical pads is one line with a count of eight, and the line still shows what one pad takes.
Footing size is a design decision that depends on the load and the soil, and this calculator does not make it. It tells you how much concrete the footing you specify will take, and reports the waste and rounding it applied on top.
V = length × width × depth
One footing run or one pad.
net = Σ (V × count)
Every run and pad added up.
order = ceil(net × (1 + waste) ÷ 0.25) × 0.25