# Water Application Rate Calculators

## Water Application Rate - Acres

Where H = the application rate; inches per hourQ = flow rate; gallons per hour

K = one acre-inch of water = 27,154 gallons per acre

to get the conversion factor divide 27,154 ÷ 60 = 452.6667 (dividing an acre-inch by 60 minutes per hour)

A = area in acres

application rate inch per hour =flow rate (gallons per minute) ÷ 452.6667area in acres

**Example calculation :**

water flow rate= 6 gallons per minute (gpm) area to irrigate = 1.8 acres (ac) 6 ÷ 452.6667 ÷ 1.8 = 0.0074 inch(es) per hour to apply 1 inch of water would require 135 minutes of irrigation time

### Water Application Rate - Acres

#### Calculation

- flow rate (gallons per hour)
- area to irrigate (acres)
- irrigation run time the amount of time the system is running in hours
- irrigation efficiency

#### Results

- the application rate in inches per hour
- amount of water applied based on system run time in inches
- the application rate in millimetres per hour
- amount of water applied based on system run time in millimetres

## Water Application Rate - Square Footage

Where H = the application rate; inches per hourQ = flow rate; gallons per hour

K = one square foot-inch of water = 0.62 gallons per square foot

to get the conversion factor divide 0.62 / 60 = 0.011167 (dividing a foot-inch by 60 minutes per hour)

application rate inch per hour =flow rate (gallons per minute) ÷ 0.011167area in square feet

**Example calculation:**

water flow rate= 6 gallons per minute (gpm) area to irrigate = 600 square feet 6 / 0.011167 / 600 = 0.895 inch(es) per hour to apply 1 inch of water would require 67 minutes of irrigation time

#### Calculation

- flow rate (gallons per hour)
- area to irrigate (acres)
- irrigation run time the amount of time the system is running in hours
- irrigation efficiency

#### Results

- the application rate in inches per hour
- amount of water applied based on system run time in inches
- the application rate in millimetres per hour
- amount of water applied based on system run time in millimetres

*one acre = 43,560 square feet*

one square foot = 144 square inches

one acre = 43,560 * 144 = 6272640 square inches

one US gallon = 0.133680555555556 cubic foot

one acre/inch of water = 27,154 US gallons

one square foot-inch of water = 0.62 US gallons

one square foot = 144 square inches

one acre = 43,560 * 144 = 6272640 square inches

one US gallon = 0.133680555555556 cubic foot

one acre/inch of water = 27,154 US gallons

one square foot-inch of water = 0.62 US gallons