Estimate roof snow pressure and total force from snow depth, density, and roof area.
| Pressure (kPa) | – |
| Force (kN) | – |
Use this calculator for a first snow load on a flat or low-slope roof. Enter depth, density in kg/m³, and area.
Pressure (kPa) = (depth ÷ 100) × density × 9.81 ÷ 1000. Force (kN) = pressure × area. Depth can be entered in centimetres (cm) or inches (in). Area can be entered in square metres (m²) or square feet (ft²). Density stays in kg/m³. Fresh snow is often around 100 kg/m³; wet snow is heavier.
This is a uniform gravity load. It does not apply a code exposure, thermal, or slope factor.
Depth: Snow depth, in cm or in.
Density (kg/m³): Snow bulk density.
Area: Roof area, in m² or ft².
Pressure (kPa): Uniform snow pressure.
Force (kN): Total vertical force on that area.
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