How does the tool decide how much product goes in each tank?

It first finds how many acres one tank covers by dividing tank size by your spray volume per acre. It then multiplies that acreage by the label rate to get the product per tank. A 300 gal tank at 15 GPA covers 20 acres, so at 32 oz/acre you add 640 oz.

What is spray volume or GPA?

Gallons per acre (GPA) is the total carrier volume, mostly water, your sprayer applies to each acre. It is set by your nozzles, pressure, and travel speed, and the product label usually specifies a recommended range such as 10 to 20 GPA.

Does it handle a partial last tank?

Yes. Most fields do not divide evenly into full tanks. The tool reports the whole number of full tanks plus the acres and product for the final partial tank, so you do not overmix and waste chemical.

Should I add product before or after filling with water?

Follow the label, but the general order is fill the tank one-half to two-thirds with water, start agitation, add products in WALES order (wettable powders, agitate, liquids, emulsifiables, surfactants), then top off. This tool gives the quantities, not the sequence.

Can I use it for ounces, fluid ounces, pints, or quarts?

Yes. The rate units are whatever you enter, so if your label rate is in fl oz/acre the product per tank and total are also in fl oz. Keep the rate and your measuring units consistent.

Herbicide / Pesticide Tank Mix Calculator

Filling a sprayer correctly means matching the chemical in the tank to the acres that tank will actually cover, not to the whole field. This calculator works out how many acres each tankful treats and how much product to pour in, including the awkward partial last tank, so every acre gets the labeled rate.

How it works

The math hinges on how many acres one tank of carrier covers:

acres per tank = tank size (gal) / spray volume (GPA)
product per tank = acres per tank × label rate per acre
total tanks = field acres / acres per tank
total product = field acres × label rate per acre

The number of tanks is split into whole full tanks plus a final partial tank sized to the leftover acres, so you mix only what you need and avoid disposing of leftover spray solution.

Example and tips

A 24 oz/acre herbicide applied at 15 GPA from a 300-gallon tank: each tank covers 300 / 15 = 20 acres and takes 20 × 24 = 480 oz of product. Treating 70 acres needs 3 full tanks (60 acres) plus a partial tank for the final 10 acres holding 150 gallons of water and 240 oz of product, and 1680 oz of product total. Always read and follow the product label for the legal maximum rate, required adjuvants, and re-entry intervals.