Footing Area for Soil Bearing
Required footing area and side dimension by soil class.
Example
You enter
- Column load (lb) 12000
- Soil class clay
You get
- Required area 8
Checked against published worked examples from: Journal of Light Construction (JLC) / Professional Deck Builder.
Details, formula, and sources
Formula or tableRequired bearing area A = P / q_allow. Allowable bearing pressure q_allow from IBC Table 1806.2 keyed to soil class (IBC 2027 Table 1806.2, values and number identical to 2021).
Source and editionIBC 2027 Table 1806.2 (identical to IBC 2021 Table 1806.2).
Free accessFree read-only access at codes.iccsafe.org.
What governsEstimate. AHJ and licensed structural engineer govern.
API field namescolumn_load_lb, soil_class, required_area_ft2
- Bearing-capacity table data/construction/soil-bearing.json keyed to soil class (IBC Table 1806.2 values)IBC 2027 Table 1806.2