What this tool does
Product labels give rates per 1,000 square feet or per acre. Sprayers hold gallons. Granular bags list a percentage. This converter does the unit arithmetic between those three so you measure the right amount, and nothing else: it does not pick a product or a rate for you. The label in your hand is the legal and agronomic authority.
Sprayable products: the math
total product = rate (oz / 1,000) × area ÷ 1,000
total spray volume = carrier (gal / 1,000) × area ÷ 1,000
product per gallon = rate ÷ carrier
product per full tank = product per gallon × tank size
tanks = ⌈total spray volume ÷ tank size⌉, the last one partial
per-acre equivalent = rate × 43.56
Worked example: 0.55 oz of Prodiamine 65 WG per 1,000 sq ft on 7,000 sq ft at 1 gal of water per 1,000 with a 4-gallon tank. Total product is 3.85 oz in 7 gallons. Each full tank covers 4,000 sq ft and takes 2.2 oz. The second tank is mixed at 3 gallons with 1.65 oz.
The active-ingredient line uses the product's percentage for dry formulations (oz ÷ 16 × a.i.%) and the label's pounds-per-gallon figure for liquids (fl oz ÷ 128 × lb a.i. per gallon). It lets you compare a sprayable product with a granular one on the same footing.
Granular products: the math
lb a.i. per 1,000 = lb a.i. per acre ÷ 43.56
lb product per 1,000 = lb a.i. per 1,000 ÷ (a.i.% ÷ 100)
total lb = lb product per 1,000 × area ÷ 1,000
Granular pre-emergents carry their active ingredient as a low percentage of an inert carrier, which is why 0.29%, 0.42% and 0.58% prodiamine bags of the same weight cover very different areas at the same active-ingredient rate. Take the target from the bag's own rate chart, then calibrate the spreader to the pounds per 1,000 this tool returns.
Where the presets come from
| Preset | What is copied | Label |
|---|---|---|
| Prodiamine 65 WG (Quali-Pro, generic Barricade) | Table 1, maximum application rate per calendar year by turfgrass species, in oz of product per 1,000 sq ft; minimum carrier of 20 gal per acre; 65% a.i. | EPA Reg. No. 53883-429, accepted 2025-11-24 |
| T-Nex 1 AQ (trinexapac-ethyl 11.3%) | Application rate table, residential and commercial turf column, in fl oz per 1,000 sq ft; 0.5–4.0 gal water per 1,000; 7.0 fl oz per 1,000 per year maximum; 11.3% a.i. | EPA Reg. No. 53883-373, accepted 2023-12-12 |
Dimension 2EW (dithiopyr) is not a preset: its current EPA label PDF does not extract to readable text, and no rate goes on this page that was not read from the stamped label. Type its rate from your own label using the Other product option.
Honest caveats
The label governs
Every preset is a copy of a label table, and labels change. Registration numbers and acceptance dates are shown so you can check the current version on the EPA Pesticide Product Label System. A generic with the same active ingredient may carry different rates, turf lists and annual limits. When the label you hold disagrees with a preset, the label wins.
Maximums are not targets
The prodiamine preset defaults to the top of each turf group's range because Table 1 is an annual maximum. Lower rates give shorter control and let you split applications through the season. The tool warns when a rate exceeds the label maximum; it does not tell you which rate to choose.
Measuring, not calibrating
This tool gives the amount per tank. It assumes your sprayer actually puts down the spray volume you entered per 1,000 sq ft, which depends on nozzle, pressure and walking speed. Check that with a water-only pass first, and use the spreader calibration tool for granular rates.
Sources
Prodiamine 65 WG Herbicide label. Control Solutions, Inc. EPA Reg. No. 53883-429, accepted 2025-11-24. EPA PPLS PDF — Table 1 annual maximum rates by turf species, carrier minimum, a.i. percentage.
Quali-Pro T-Nex 1 AQ label. Control Solutions, Inc. EPA Reg. No. 53883-373, accepted 2023-12-12. EPA PPLS PDF — Application rate table, spray volume, annual maximum, rate adjustment guidance.
Informational only — not professional agronomic or pesticide advice. Always read and follow product label directions. Last reviewed: October 2026.
Frequently asked questions
How much Prodiamine 65 WG do I put in a 4-gallon sprayer?
Multiply the label rate for your grass by the square feet one tank covers, then divide by 1,000. At 1 gallon of water per 1,000 sq ft a 4-gallon tank covers 4,000 sq ft, so a tall fescue lawn at 0.55 oz per 1,000 takes 2.2 oz per tank. The converter does this for any rate, spray volume and tank size, and flags anything above the label's Table 1 maximum for your turf.
What does 0.58% prodiamine on a granular bag mean in pounds per 1,000 sq ft?
The percentage is the share of the bag that is active ingredient. To match a target of 1.5 lb of prodiamine per acre, you need 1.5 ÷ 43.56 = 0.0344 lb of active ingredient per 1,000 sq ft, which at 0.58% is 0.0344 ÷ 0.0058 = 5.9 lb of product per 1,000 sq ft. Use the bag's own rate chart as the target; the granular tab does the division.
Why does the T-Nex rate differ by grass?
The label's application rate table lists a different residential-turf rate for each species because they respond to trinexapac-ethyl differently: 0.6 fl oz per 1,000 sq ft on Kentucky bluegrass, 0.75 on turf-type tall fescue, 1.0 on perennial ryegrass, 0.25 on hybrid bermudagrass and zoysiagrass. The label also caps the year at 7.0 fl oz per 1,000 sq ft and allows a 50% adjustment up for spring flush or down for stressed turf.
Can I use a preset for a different brand of the same active ingredient?
Only as a starting point. Rates are set per registered product, and another brand's label can differ in concentration, turf list and annual maximum even when the active ingredient matches. Choose the Other product option, type the rate printed on the label you are holding, and read that label's own limits.