Why 1 mm = 1 L/m²
The conversion between millimeters and liters per square meter is based on simple geometry:
Mathematical Proof:
- • 1 square meter = 1,000,000 square millimeters
- • 1 mm of rain depth across 1 m² = 1,000,000 mm² × 1 mm = 1,000,000 mm³
- • 1,000,000 mm³ = 1,000 cm³ = 1 liter
- • Therefore: 1 mm = 1 L/m²
Source: Australian Bureau of Meteorology - Design Rainfall Guidelines
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Common Rainfall Conversions
| mm | L/m² | inches | Description |
|---|---|---|---|
| 0.25 | 0.25 | 0.01 | Trace precipitation |
| 2.5 | 2.5 | 0.10 | Light rain |
| 10 | 10 | 0.39 | Moderate rain |
| 25 | 25 | 0.98 | Heavy rain |
| 50 | 50 | 1.97 | Intense rain |
| 100 | 100 | 3.94 | Extreme rainfall |