Platte County Weed and Pest

Calibration Calculator

The following calculator is ideal for backpack sprayers:

1/128 Sprayer Calibration Tool

Use this tool to calibrate a backpack or hand sprayer using the 1/128 method. It will walk you through timing your spray pass, calculating gallons per acre, and determining how much pesticide to add to your tank.

Always read and follow the pesticide label. The label is the law.

Step 1: Choose Your Calibration Plot

Plot area: 340.00 square feet

The 1/128 method uses approximately 340 square feet.

Step 2: Time Your Spray Pass

Fill your sprayer with clean water. Spray the calibration plot using your normal walking speed, pressure, and spray pattern. Enter your time below. Three trials are recommended.

Average spray time: 0.00 seconds

Step 3: Collect Your Spray Volume

Spray into a container for the average number of seconds calculated above. Measure the collected water in ounces.

Your sprayer is applying: 0.00 gallons per acre

In the 1/128 method, ounces collected equals gallons per acre when using a 340 square foot plot.

Step 4: Calculate Product Needed

Add this amount of product to your tank:
0.00 ounces

This video from the Wyoming Weed and Pest Council is a great tool for calibrating your 4-wheeler:

There can be many variables involved in calibrating your equipment. If you have any questions call our office at 307.322.3210!