Spray Mix Calculator
Work out how much product to mix into a sprayer tank for the label rate.
About the Spray Mix Calculator
Labels give a dose per hectare (or acre) with a spray volume, or a concentration per litre. Product per tank = (dose per area ÷ spray volume per area) × tank size. Calibrate the sprayer to know your actual spray volume. Never exceed the label rate; it's the legal limit in most countries.
The formula
Per tank = rate per ha ÷ water per ha × tank litres
Worked example
Example: Product per tank = 18 ml or g
- Inputs: Label rate given as: Amount per area; Label rate (ml or g): 550 per ha or per L; Spray volume: 550 L per ha; Tank size: 18 L.
- Formula: Per tank = rate per ha ÷ water per ha × tank litres
- Result: Product per tank = 18 ml or g
Things to keep in mind
- The product label is the law: check crop, dose, pre-harvest interval and safety directions.
Questions people ask
How do I calibrate a knapsack sprayer?
Spray a measured area with water and see how much was used.
Can I mix two products?
Only if both labels allow it; do a jar test first.