Soil Bearing Capacity Calculator
Enter the total load and foundation base area to calculate the average base pressure (kPa) and check it against the allowable soil bearing capacity for a quick foundation check.
Input Data
Results
At a glance:Average base pressure q = total load (kN) ÷ base area (m²), in kPa (= kN/m²). The foundation safety rule is q ≤ allowable soil bearing capacity q_a. If exceeded, widen the base, use piles or improve the ground. Allowable capacity depends on geology: Hong Kong fill is commonly 100–150 kPa and intact rock hundreds to thousands of kPa; the actual value must come from a geotechnical investigation report.
Formula
Base pressure = total load / base area
Safe if pressure ≤ allowable bearing
$$q = \frac{P}{A}$$$$q \le q_a$$How to Use
- Enter the total load (kN).
- Enter the base area (m²).
- Enter the allowable soil bearing capacity (kPa).
- The tool outputs the base pressure and check.
Case Studies
Single column footing
500 kN load, 10 m² base, 150 kPa allowed.
Pressure 50 kPa, below the limit, safe.
Soft-soil foundation
800 kN load, 4 m² base, 100 kPa allowed.
Pressure 200 kPa, exceeds limit; widen base or use piles.
FAQ
How to convert kPa to kg/m²?
1 kPa = 1 kN/m² ≈ 102 kg/m², so 150 kPa ≈ 15,300 kg/m².
Where does the allowable capacity come from?
It must be determined by a geotechnical investigation (plate load test, SPT, etc.); this calculator's value is for preliminary estimation only.
Related Tools
References
Content review: Calculatorism Construction Team. Results are for reference only; please refer to the relevant authorities for the official figures.