Plan new footings with clear sizing steps today. Enter loads, soil capacity, and geometry fast. Get width, area, and pressure checks in seconds easily.
| Footing option | Dead (kN) | Live (kN) | qallow (kPa) | Length (m) | Thickness (m) | Rounded step (m) |
|---|---|---|---|---|---|---|
| Strip footing | 650 | 250 | 150 | 3.0 | 0.6 | 0.05 |
| Rectangular pad | 900 | 300 | 200 | 2.5 | 0.7 | 0.10 |
| Square pad | 750 | 150 | 180 | — | 0.5 | 0.05 |
Values are illustrative for concept planning only. Always confirm with a qualified engineer and local code requirements.
Self weight depends on plan size, so the calculator refines width with a short iteration to stabilize results.
A footing spreads column or wall loads into the soil so contact pressure stays within an allowable bearing value. This calculator estimates the required plan area from service loads and a selected design bearing, then converts that area into a width (or square side) based on your chosen geometry.
Typical concept inputs include dead load from self weight and finishes, live load from occupancy, and any permanent equipment. For early planning, many projects check multiple cases, such as a lighter service case and a heavier “future change” case. Keep all loads in kN and confirm that the geotechnical report bearing value is in kPa (kN/m²).
Allowable bearing values often already include safety, settlement considerations, and site variability. The optional safety factor feature lets you reduce the bearing further for conservative concept comparisons, especially when the bearing value is uncertain. If you apply an extra factor, document it clearly in the exported report for review.
Footing self weight can be meaningful for large pads. Because self weight depends on footing area, the calculator iterates the plan size using your assumed thickness and concrete unit weight. If you are still selecting a thickness, run a sensitivity check by trying two values, such as 0.5 m and 0.8 m, and compare changes in width and utilization.
Utilization is the ratio of actual contact pressure to the selected design bearing. Values below 1.0 indicate the concept width satisfies the bearing check with the entered assumptions. Final design typically also verifies eccentric loading, punching and one‑way shear, sliding, overturning, reinforcement, frost depth, and settlement. Use the rounding increment and minimum width controls to keep results buildable and consistent with local practice.
No. It is for concept sizing based on bearing pressure and an optional self‑weight estimate. Final designs require geotechnical confirmation, code checks, shear design, reinforcement detailing, and settlement verification.
Thickness is used only to estimate footing self weight. Larger footings weigh more, which slightly increases required area. If you enter zero thickness, the calculator treats self weight as zero.
Use the allowable bearing from a site geotechnical report when available. If you only have a preliminary value, use the safety factor option for conservative comparisons and clearly label the assumption in exports.
Use strip footing for continuous walls where length is fixed. Use rectangular pad when one plan dimension is constrained by layout. Use square pad for isolated columns when space allows symmetric spreading.
It rounds the computed width up to a practical step, such as 0.05 m or 0.10 m. This helps align with formwork and site measurement habits, and it avoids undersizing due to rounding down.
Increase width, increase length, reduce loads, or use a higher confirmed bearing value. Also review whether the safety factor was applied intentionally. If the result stays high, seek engineering review.
No. It performs a bearing‑based sizing and pressure check only. Settlement, eccentricity, and structural checks can govern and may require a larger footing than the concept result.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.