How many gallons does a rainfall depth represent?
Enter rain depth and the area it covered to calculate the geometric volume in U.S. gallons and litres. No location, account, or weather service is required.
Rain depth multiplied by area
Metric geometry is direct: one millimetre over one square metre represents exactly one litre. U.S. calculations use the exact definitions of 231 cubic inches per U.S. gallon and 1,728 cubic inches per cubic foot.
litres = area m² × rain mmU.S. formulaU.S. gallons = area ft² × rain inches × 48 ÷ 77Example: 10 millimetres over 10 m² represents 100 litres, approximately 26.42 U.S. gallons, geometrically. Runoff, interception, evaporation, uneven gauge exposure, and infiltration are not calculated.
Continue with the measurement you need.
Use one tool or follow the full pathway. These tools calculate from entered or measured values; they do not decide whether or how much to water.
- 1Measure source flow
Bucket-test a faucet, hose, or installed setup.
- 2Calculate drip output
Multiply entered emitter count, rate, and runtime.
- 3Connect flow to volume
Carry flow into runtime, volume, area-depth, rainfall, and a private record.
- 4Convert rain to volume
Calculate litres or U.S. gallons from entered rain depth and area.
Current tool - 5Convert volume to depth
Calculate equivalent geometric depth over an entered area.