Pesticide Dilution & Mixing Chart
Printable pesticide dilution chart: 1:100 and 1:32 to 1:256 ratios as oz per gallon, 1% to 3% mixes, backpack fills, and hose-end sprayer jar math.
Frequently asked questions
How many ounces per gallon is a 1:64 dilution?
2 fl oz of concentrate per US gallon. The whole ladder is one identity — 128 ÷ N — because a US gallon holds 128 fl oz: 1:32 gives 4 oz, 1:64 gives 2 oz, 1:128 gives 1 oz, 1:256 gives 0.5 oz. Fulton Distributing's published dilution ratio chart prints the same figures from the other side of the colon: 2 ounces of concentrate to 128 ounces of water at 64-to-1, 1 ounce at 128-to-1, 0.50 ounce at 256-to-1. Pesticide Environmental Stewardship works off the identical 128-ounces-per-gallon basis. The sheet above prints the ladder so you read a row instead of dividing. Which ratio applies is on the product label — the label rate governs.
How do I convert a percent label rate to ounces per gallon?
Multiply the percent by 1.28, which is just the 128 fl oz in a gallon divided by 100. A 2% solution is 2.56 oz per gallon (printed field-rounded as 2.6) and a 2.5% solution is 3.2 oz. Online Pest Control Courses publishes both worked examples; Pesticide Environmental Stewardship reaches the same 2.6 oz by multiplying 0.02 × 128; The Nature Conservancy's liquid-herbicide mixing chart prints 2.6 and 3.2 in its per-gallon column. Bigger vessel, same arithmetic: multiply the per-gallon amount by the number of gallons. For a percent or a tank size the strip does not print, the pesticide dilution calculator takes any value.
How much concentrate does a 4-gallon backpack sprayer take?
Four times the per-gallon figure: 4 oz at 1:128, 8 oz at 1:64, 16 oz at 1:32 — the backpack column on the sheet. Fulton's chart states the scaling rule outright: for mixes in multiple gallons, multiply the chemical amount by the number of gallons. A 2.5-gallon hand can is the same sum at ×2.5; a 32-oz bottle is a quarter-gallon, so it is the per-gallon amount ÷ 4. The label rate still governs the ratio. If you also need the water half of the mix, use the dilution calculator; to find what your own backpack actually puts out, see backpack sprayer calibration.
What is a 1:64 dilution in metric — mL per litre?
A ratio carries no units, so 1:64 is 1 part concentrate to 64 parts water in whatever you measure with: 1,000 ÷ 64 ≈ 15.6 mL per litre, exactly as 128 ÷ 64 = 2 oz per US gallon. Fulton's chart supplies the bridging equivalents — 128 fl oz = 1 gallon = 3.8 litres, 1 fl oz = 2 tbsp = 30 mL, 3 tsp = 1 tbsp = 15 mL — so that 2 oz per gallon also reads as roughly 60 mL of concentrate per gallon. Percent rates are unit-free the same way: 2% is 20 mL per litre just as readily as it is 2.56 oz per gallon.
Is a hose-end sprayer setting the same number as the oz-per-gallon column?
Same unit, yes. Montana State University Extension describes hose-end systems as working in "ounces per gallon over given unit area", with the sprayer jar "generally marked with two scales: fluid ounces and gallons", and notes that on a dial-in model the setting is the dilution rate printed on the product label. So the figure a hose-end asks for is the same oz-per-gallon number the ratio and percent columns produce: 1:64 → 2 oz per gallon, 2% → 2.56 oz. What no chart can supply is which rate belongs on your product — that is the label's, and the label governs.
Chart or calculator — which should I use?
The chart is the lookup: fixed, pre-checked rows for the ratios and percents that recur, sized to print and keep in the truck. The pesticide dilution calculator is the any-value version — any rate, any tank size, and it returns the water alongside the concentrate. Neither knows your product; the rate comes from the label. For the numbers either one feeds, spray coverage turns a per-1,000-sq-ft rate into finished gallons and tank loads, the active-ingredient ppm converter restates a mix as ppm, and the herbicide tank-mix calculator handles oz/acre label rates.
Sources
- Dilution Ratio Chart (PDF). Fulton Distributing. Retrieved .
- Mixing Chart for Liquid Herbicides (PDF). The Nature Conservancy. Retrieved .
- Calibration — Doing the Math. Pesticide Environmental Stewardship. Retrieved .
- How to Calculate Pesticide Dilution Ratios. Online Pest Control Courses. Retrieved .
- Calibrating Home and Garden Sprayers (MT200015AG, rev. 09/23). Montana State University Extension. Retrieved .