Pesticide Mixing Calculator
Determine how much pesticide concentrate to add to your spray tank for a given field area, application rate, and tank size. Use it every time you prepare a tank mix to avoid under- or over-dosing.
Last updated: September 2026
Product per Tank Load
40 oz
Formula below · 2 sources (usda.gov, Wikipedia) · Updated Sep 2026
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About this calculator
Correct pesticide mixing matches the product added to each tank to the area that tank will cover. One full tank covers tankSize ÷ waterRate acres, so each full tank needs applicationRate × (tankSize ÷ waterRate) ounces of active ingredient; dividing by the concentration converts active ingredient into ounces of the commercial product. If the whole job needs less than one tank (sprayArea × waterRate is smaller than the tank), only that volume is mixed. The formula is: Product per Tank (oz) = applicationRate ÷ concentration × min(tankSize, sprayArea × waterRate) ÷ waterRate. Most pesticide labels give the rate as ounces of product per acre: keep "Product per acre" (the default) and no conversion is applied. Only if you are working from a rate of active ingredient per acre (for example a recommendation stated in oz a.i./acre) choose the product's active-ingredient share, and the calculator converts it to product. Choosing an active-ingredient option for a label product rate would overdose the tank, so check which one your rate is. The number of tank loads is sprayArea × waterRate ÷ tankSize, and the total product for the job is sprayArea × applicationRate ÷ concentration. Always calibrate your sprayer nozzles before mixing to ensure the water application rate is accurate.
How to use
You need to spray 10 acres at 8 oz/acre (a product rate from the label, so keep "Product per acre"), with a 100-gallon tank and a water rate of 20 gal/acre. Step 1 — Acres per tank: 100 / 20 = 5 acres. Step 2 — Product per tank: 8 oz/acre × 5 acres = 40 oz. Step 3 — Tank loads: 10 × 20 / 100 = 2 full tanks, so the job uses 80 oz in total. Using the formula: 8 / 1 × min(100, 10 × 20) / 20 = 8 × 100 / 20 = 40 oz per tank load. Only if 8 oz/acre were a rate of active ingredient and the product were 50% a.i. would you choose that option, and the tank would then need 80 oz of product.
Frequently asked questions
How do I calculate how much pesticide to add per tank load for my sprayer?
Use the rate on the product label, which is almost always ounces (or pints, quarts) of product per acre, and keep "Product per acre" selected. Each full tank covers tank size ÷ water rate acres, so product per tank = label rate × acres per tank. For example, 8 fl oz/acre with a 100-gallon tank at 20 gal/acre: 100 ÷ 20 = 5 acres per tank, 8 × 5 = 40 fl oz per tank. Total product for the job is area × label rate, and tank loads are area × water rate ÷ tank size. The label is a legal document: never exceed its maximum rate, and convert pints or quarts to fluid ounces (1 pt = 16 fl oz, 1 qt = 32 fl oz) before entering them.
What is the water application rate and why does it matter for pesticide mixing?
The water application rate, measured in gallons per acre, is how much spray solution your equipment deposits on each acre of crop. It affects droplet coverage, canopy penetration, and drift risk. Typical field sprayers run 10–20 gal/acre, while orchard airblast sprayers may use 50–100 gal/acre. The water rate determines how many tank loads you need per field, which directly sets how much concentrate goes into each individual tank. If your actual water rate differs from your assumed rate — due to nozzle wear or speed changes — your pesticide dose per acre will be off.
Why is it important to calibrate a sprayer before mixing pesticides?
Calibration verifies that your sprayer delivers the intended volume of water per acre at your operating speed and pressure. Even brand-new nozzles can vary ±5–10% from their rated output, and worn nozzles may deliver 20% or more above the rated rate. An uncalibrated sprayer means your calculated mix ratio produces the wrong field dose — potentially causing crop damage from overdosing or pest survival from underdosing, both of which carry regulatory and economic consequences. Calibrate at the start of each season and whenever nozzles are replaced.
When should I pick an active-ingredient option?
Only when the rate you have is stated as active ingredient (a.i.) per acre, for example from an extension recommendation written as "0.5 lb a.i./acre". The calculator then divides by the product's active-ingredient share to get product. If your rate comes from the product label, it is already a product rate: choosing an active-ingredient option would multiply the dose (2× at 50%, 10× at 10%).
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