Concrete Footing Calculator

Calculate concrete volume, bag count, weight, cost, and truck loads for rectangular strip footings, pad footings, and round pier footings.

Total linear run of the footing Enter a positive value
Typical 12–24 in for residential Enter a positive value
Must extend below frost line Enter a positive value
Number of identical footings
Average US: $130–$165/cu yd
Average US: $5–$8 per 80 lb bag
  1. Choose your footing type — Strip/rectangular for wall footings and continuous foundations; Square pad for isolated column bases; Round/pier for sonotube or drilled piers.
  2. Select your unit system — Imperial (feet & inches) or Metric (metres & centimetres) using the toggle at the top.
  3. Measure your footing — Length is the total linear run. Width and depth are cross-section dimensions. For round footings, measure the tube or hole diameter.
  4. Enter quantity — If you have multiple identical footings (e.g. 6 deck posts), enter that number and the calculator multiplies automatically.
  5. Optional: Add cost estimate — Tap "Add cost estimate" to enter local ready-mix and bag prices. The calculator will compare both options for you.
  6. Read results — The primary result is in cubic yards. Bag counts use ceiling rounding so you never under-order. The 10% waste row accounts for spillage and overfill.
  7. Copy or download — Use "Copy results" to paste into a quote, or "Download report" for a branded PDF you can share with your supplier or client.

All results are estimates. Always verify with your contractor or engineer before ordering ready-mix.

Rectangular / Strip footing:

Volume (cu ft) = Length (ft) × Width (ft) × Depth (ft) × Quantity Volume (cu yd) = Volume (cu ft) ÷ 27 Volume (cu m) = Volume (cu ft) × 0.0283168

Square Pad footing:

Volume (cu ft) = Side (ft) × Side (ft) × Depth (ft) × Quantity Volume (cu yd) = Volume (cu ft) ÷ 27

Round / Pier footing:

Volume (cu ft) = pi × (Diameter ÷ 2)² × Depth (ft) × Quantity Volume (cu yd) = Volume (cu ft) ÷ 27

Bag counts & truck loads:

60 lb bag = 0.45 cu ft → bags = ceil( cu ft ÷ 0.45 ) 80 lb bag = 0.60 cu ft → bags = ceil( cu ft ÷ 0.60 ) 1 truck = 10 cu yd → trucks = cu yd ÷ 10

Weight, cost & waste:

Weight (lbs) = cu ft × 150 Waste (cu yd) = cu yd × 1.10 Ready-mix cost = waste cu yd × price/yd Bag cost = ceil(waste cu ft ÷ 0.60) × bag price

Unit conversions: 1 ft = 12 in = 30.48 cm · 1 cu yd = 27 cu ft · 1 cu ft = 0.0283168 cu m · Concrete density ≈ 150 lb/cu ft