Rain to Snow Calculator — Rainfall to Snowfall Equivalent
Convert a rainfall reading into the equivalent snowfall depth. Enter the liquid precipitation amount and adjust the snow-to-liquid ratio for your type of snow — wet and heavy (3–6), standard (10), or dry powder (15–30).
Unit
in
Depth of snow that corresponds to the given rainfall
- 1
Snow-to-liquid ratio (SLR)
10Each unit of liquid rainfall produces this many units of snow depth. - 2
Snowfall equivalent
1 × 10 = 10
How does this calculator work?
Snowfall depth = Rainfall × Snow-to-liquid ratio. The standard ratio is 10 (1 inch of rain → 10 inches of snow). Wet heavy snow uses SLR 3–6; dry powder can reach 15–30. Enter rainfall and ratio to get the snowfall equivalent in inches or millimetres.
Formula
How this is calculated
Rain and snow are both precipitation, and meteorologists routinely convert between them using the snow-to-liquid ratio (SLR). The standard SLR of 10:1, used by the US National Weather Service, means that 1 inch (25.4 mm) of liquid rain would produce 10 inches (254 mm) of freshly fallen snow of average density. This reflects the air trapped in the snowflake lattice: snow is mostly air, so the same liquid water spreads into a much deeper layer when frozen.
The ratio is not fixed. Wet heavy snow forming just below 0 °C has dense, partially melted crystals — its SLR can be as low as 3–6. Very cold, dry powder snow at −15 °C or below has complex airy dendrites and can reach SLR 20–30. Operational meteorologists refine the SLR from atmospheric temperature profiles; forecast discussions often include the expected SLR for a storm event.
This calculator performs the direct multiplication: snowfall = rainfall × SLR. It does not model temperature, humidity or elevation. Enter the SLR from a local forecast or use 10 for a standard estimate.
Frequently asked questions
The SLR is the depth of snow produced by a given depth of liquid water. An SLR of 10 means 1 inch of rain becomes 10 inches of snow. The standard value is 10, but wet heavy snow can be as low as 3 and very dry powder can exceed 20.
The 10:1 rule is a useful planning approximation and the standard used for historical comparison, but real SLR varies with air temperature and crystal type. Wet storms often produce SLR 4–7; cold dry arctic events can reach 20+. Use local forecaster SLR values for precision.
Yes: divide snowfall by the SLR. For example, 15 inches of snow with SLR 10 contains 1.5 inches of liquid water. Use this to estimate runoff or water storage from a snowpack.
Also known as
TG we-Calculate Editorial Team. (2026). Rain to Snow Calculator — Rainfall to Snowfall Equivalent [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/rain-to-snow-calculator
TG we-Calculate Editorial Team. "Rain to Snow Calculator — Rainfall to Snowfall Equivalent." TG we-Calculate. 2026. https://we-calculate.com/calculator/rain-to-snow-calculator.
TG we-Calculate Editorial Team, "Rain to Snow Calculator — Rainfall to Snowfall Equivalent," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/rain-to-snow-calculator
@misc{wecalculate_rain_to_snow_calculator, title = {Rain to Snow Calculator — Rainfall to Snowfall Equivalent}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/rain-to-snow-calculator}}, year = {2026}, note = {TG we-Calculate} }
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