Rainfall Converter
Convert between mm, inches, liters per square meter, and gallons per square foot of rainfall.
Type in any field — the others update instantly.
Rainfall measures how much water falls on a surface.
Key relationship:
- 1 mm of rain = 1 liter per square meter (exact)
- This is because 1 mm depth × 1 m² area = 0.001 m³ = 1 liter
Conversions:
- 1 inch of rain = 25.4 mm (exact)
- 1 inch of rain = 25.4 liters per m²
- 1 mm of rain = 0.03937 inches
- 1 gallon per sqft = 40.746 liters per m² = 40.746 mm
Practical references:
| Description | mm | inches |
|---|---|---|
| Light drizzle | 0.1–2.5 mm | 0–0.1" |
| Light rain | 2.5–7.5 mm | 0.1–0.3" |
| Moderate rain | 7.5–50 mm | 0.3–2" |
| Heavy rain | 50–100 mm | 2–4" |
| Very heavy rain | 100+ mm | 4+" |
Annual rainfall examples:
| Location | Annual (mm) | Annual (in) |
|---|---|---|
| London | ~600 mm | ~24" |
| New York | ~1,270 mm | ~50" |
| Sydney | ~1,215 mm | ~48" |
| Mumbai | ~2,400 mm | ~95" |