# Select a Calculator

These irrigation calculators will help compute your irrigation needs based on your growing practices, types of soil, and vegetation.

#### Popular

- Drip Line Rate: Water application rate of drip irrigation.
- Sprinkler Application Rate: Application rate based on nozzle diameter and spacing.
- Water Application Rate: Water application rate from a given flow and area.
- Nozzle Requirements: Find the flow rate using a given pressure and diameter, or find the nozzle diameter for a given pressure and flow rate.
- Pipeline Size/Pressure Loss: Calculate the pressure loss in a pipe with evenly spaced outlets, such as a sprinkler lateral or a manifold, or minimum pipe size in the same based on the maximum allowable pressure loss.

#### Irrigation Management Calculators

- Irrigation Frequency: maximum interval allowed between irrigations. This is dependent on soil type, root zone depth, and the water use rate of the crop.
- Set Times: set time required to fulfill a given water application, irrigation area, and flow rate.
- Water Depth: Depth of water applied to a specified area over the specified time span based on the given flow rate.
- Water Application Rate: Application rate using the flow rate on an area.

#### Drip

- Drip Line Rate: Water application rate of drip lines.
- Drip Design for Landscapes: Determine how much water to apply to individual plants with drip emitters.

#### Sprinkler

- Sprinkler Application Rate: Sprinkler application rate based on nozzle diameter and spacing.
- Nozzle Requirements: Find the flow rate using a given pressure and diameter, or find the nozzle diameter for a given pressure and flow rate.
- Lateral Friction Loss: Find the flow rate, pipe length and friction loss based on a sprinkler lateral.
- Hand Move Sprinklers: Find recommended values for hand move sprinklers, such as set times, nozzle and pressure losses.
- Sprinkler Density: Find the number of sprinkler heads per area for rectangular or triangular spacing.
- Sprinkler Discharge Rate: Learn how to estimate a single sprinkler's discharge rate by setting up an experiment using two sprinklers, 4 cans and a measuring container.
- Traveling Big Gun Sprinkler: Calculate the net water application for a given flow rate, efficiency percentage, lane width, and travel speed.
- Traveling Sprinkler: Estimate the the total number of irrigated acres per hour based on lane spacing and travel speed.

#### Center Pivot

- Percent Timer Setting: Use this calculator to calculate an approximate timer setting to apply a particular depth.
- 1" Application Time: Calculate the irrigation time to apply one inch of water with a center pivot.
- Center Pivot Acreage: Calculate the area underneath a center pivot.
- Pivot Full Rotation Time: The time that it takes for a 360 degree rotation of a center pivot.
- System Pumping Requirements: Calculate the system capacity (flow rate) required to meet the demands of a field.

#### Residential

- Drip Design for Landscapes: Determine how much water to apply to individual plants with drip emitters.
- Garden Hose Flow Rate Calculate the flow rate and application time for a garden hose, based on hose size and supply pressure.
- Lawn Water Management Find the application depth and operation time for a specific grass type, precipitation rate, and daily water use. Also provides suggested application depths and operation times for multiple water periods.
- Tree Water Management Find a watering period and water quantity for a tree type, tree spread diameter, and daily water use. The results give a suggested water management schedule for watering periods and a corresponding water quantity.

#### General Design Calculators

- Field Area: Determines the area of rectangular, triangular, circular and trapezoidal fields.
- Irrigatable Area: The land area that can be irrigated with a given flow of water.
- Irrigation Frequency: The maximum interval allowed between irrigations.
- Irrigation Run Time: Determine the length of time that an irrigation system must run to apply enough water to replace the water lost to evapotranspiration.
- Required Water Pump Horsepower: Estimate the brake horsepower and total power (hp) requirements of the electric motor used to power an irrigation water pump.
- System Pumping Requirements: Calculate the system capacity (flow rate) required to meet the demands of a field.
- NPSHA: determines the absolute pressure at the pump impeller.
- Total Dynamic Head: This calculator finds the pressure required at the pump, and the head that the pump must generate.
- Pipe Size Estimate: Determined by measuring the circumference of the pipe with a string or a flexible tape measure.
- Pipe Velocity and Diameter: Calculate the velocity of water in a pipe and calculate the diameter of a pipe required for 5 fps pipe velocity.
- Pipeline Pressure Loss: Calculates the pressure or friction loss along a given length of pipeline with a specified inside diameter and the minimum pipe size to limit pressure loss to a specified value.
- Pressure Loss with Outlets: Calculates friction loss in a pipe with equally spaced outlets and the minimum pipe size for a pipe with equally spaced outlets.
- Fitting Pressure Loss: The equivalent feet of pipe to add to the pressure loss equation.
- Pipeline Pressure Rating: Calculate the maximum operating pressures at 74 deg F (23 deg C).
- Required Maximum Flow Rate: Flow rate onto a specified area to meet the maximum water use rate requirements.
- System Capacity: Calculate the system capacity (flow rate) required to meet the demands of a field.
- Water Application Rate: Water application rate using the flow rate on an area.
- Water Depth: Depth of water applied to a specified area over the specified time span based on the given flow rate onto the field.
- Water Hammer: Surge pressure due to a sudden shutting of a valve, or water hitting the end of a pipe.
- Water Supply Design: Estimate of the water flow requirements to replace water lost to evapotranspiration.

#### Water Measurement Calculators

- Cipolletti (Trapezoidal) Weir: Flow rate for a Cipolletti weir. The weir opening has a flat bottom and sides that have a particular slope.
- 90° Triangular Notch Weir: Flow rate of a 90° triangular notch weir. The opening to this weir is a 90 degree triangular notch.
- Parshall Flume: Flow rate for a Parshall Flume. It can be identified by both a section that has a contraction in the width of the flume as well as a dip in the elevation of the bottom of the flume.
- Rectangular Contracted Weir: Flow rate for a rectangular contracted weir. A rectangular contracted weir has a rectangular opening where the sides are straight up and down.
- Rectangular Submerged Orifices: Flow rate of water through a rectangular submerged orifice. A submerged orifice is an underwater hole that water goes through. In this case the hole has a rectangular shape.
- Trapezoidal Flume: Flow rate for a trapezoidal flume. A trapezoidal flume has a flat bottom with sloped sides that contract in the center.

#### Chemigation Calculators

- Chemical Injection Rate (Volume): Calculate the injection rate based on the volume per area.
- Chemical Injection Rate (Mass): Calculate the injection rate based on the weight per area.
- Chemical Injection Rate (Water Chemistry Control): Calculate the the injection rate for water chemical solutions.
- Maximum Solution Concentration: Find the solution concentration in the irrigation lines for a given chemical injection rate and water flow rate.
- Mixing Dry Chemicals: Calculate how much dry chemical to mix with water, depending on your water requirements.
- Batch/Bulk Application: Calculates the chemical injection rate for batch or bulk chemical applications.
- Minimum Batch Volume: Minimum amount of water that must be mixed with dry chemicals in order to get the chemicals dissolved into solution.
- Calibration: Calibrate your injection pumps by calculating the estimated fill time of a container using the pump's injection rate.
- Quantity Per Sprinkler Setting: Determine the irrigated area, and either the fertilizer or the herbicide application based on the characteristics of the area's irrigation system.