Nozzle Flow Rate Calculator

This worksheet is for educational purposes. The University of Missouri is not responsible for any actions taken as a result of using this worksheet.


  • Fill out all of the fields in the yellow-shaded area, then click the “Calculate” button. (If you’re unsure of the definitions of any of the inputs, please see the Worksheet definitions below.)
  • Results will appear in the green-shaded area.
  • After viewing your results, you may change some or all of your inputs and recalculate the results.
  • Please be patient while the worksheet performs the calculations — it may take a few seconds for the page to reappear.
  • Return to G1270.
1. Sprayer application rate gallons/acre
2. Field speed mph
3. Width sprayed by each nozzle inches
4. Nozzle flow rate
( line 1 x line 2 x line 3 ) ÷ 5940

Worksheet definitions

  • Sprayer application rate — A recommended range of sprayer application rates, in gallons per acre, is given on the pesticide label. From that range, choose the rate that is compatible with your spraying equipment.
  • Field speed — Choose a speed that can be maintained at all times. A 10 percent reduction in speed will result in a similar overapplication of pesticides. Where speed must be reduced for a short period at the end of a pass through the field or in other situations, a small reduction in engine speed is preferable to selecting a lower gear. Reducing the engine speed causes the nozzle flow rate as well as the travel speed to decrease, although not proportionately. If slowing is frequently necessary, calibrate the sprayer for the slower speed.
  • Width sprayed by each nozzle — The width sprayed by each nozzle on a broadcast spray boom is the distance between nozzles. If a sprayer has nozzles spaced every 20 inches on the boom, the width sprayed by each nozzle is 20 inches. If a sprayer has several nozzles that will be used to spray each row, such as sprayers used to apply insecticides to row crops, then the width sprayed by each nozzle is the distance between rows divided by the number of nozzles used to spray each row. If the sprayer is a band sprayer and the labeled rate applies to the actual area sprayed, the width is the width of the band. If the sprayer is a band sprayer and the labeled rate applies to the total area covered, the width is the spacing between rows.