Glyphosate 41% Dilution Rate Calculator
Dilute 41 percent glyphosate to a target ounces-per-acre rate, size the tank mix and carrier volume, and add the right ammonium-sulfate conditioner.
How This Calculation Works
Glyphosate 41 percent is a liquid concentrate labeled in ounces or quarts per acre of the formulated product, not of active ingredient. Product per tank is the ounces-per-acre rate times acres per tank, divided by 128. Carrier volume is set by the calibrated GPA and stays independent of the product rate.
Field Calibration & Rate Reference Chart
| Ground speed | Nozzle pressure | Typical GPA | Droplet class |
|---|---|---|---|
| 4 mph | 20 psi | 12 | Coarse |
| 5 mph | 25 psi | 14 | Coarse |
| 6 mph | 30 psi | 15 | Medium |
| 7 mph | 35 psi | 16 | Medium |
| 8 mph | 40 psi | 18 | Medium |
| 9 mph | 45 psi | 19 | Fine |
| 10 mph | 50 psi | 20 | Fine |
| 12 mph | 55 psi | 22 | Fine |
| 14 mph | 60 psi | 24 | Very fine |
| 16 mph | 65 psi | 26 | Very fine |
Common Questions
How much 41 percent glyphosate do I use per acre?
Annual weeds often take 32 to 48 ounces per acre, while perennials and hard-to-kill species may need 64 to 96 ounces. The label lists rates by weed species and size. Convert to ounces per acre before calculating the tank.
Why add ammonium sulfate to a glyphosate tank?
Ammonium sulfate ties up calcium, magnesium and iron ions in hard water that would otherwise bind glyphosate and reduce its activity. Add it first, at 8.5 to 17 pounds per 100 gallons, and let it dissolve before adding the glyphosate. Soft water may need little or none.
Can I tank-mix glyphosate with 2,4-D?
Yes, the two are commonly mixed for burndown, but check the label for compatibility and mixing order. Add the ammonium sulfate first, then the glyphosate, then the 2,4-D, keeping agitation running. Some formulations antagonize each other, so a jar test is worth the few minutes.
Does rain after spraying wash off glyphosate?
Glyphosate needs about 30 minutes to 6 hours of rain-free time depending on the formulation and rate. Rainfastness improves with a quality surfactant and warm, humid conditions. If rain comes too soon, expect reduced control and plan a follow-up.