Glyphosate Mixing Ratio Calculator
Calculate the exact amount of glyphosate herbicide needed per gallon or liter of water. Perfect for clearing weeds, brush, and invasive plants safely.
Sprayer & Target Details
Enter your water volume and target weed type to calculate the exact herbicide needed
How much water are you mixing in your sprayer?
Choose your preferred measurement unit.
Select the type of vegetation you are treating.
Mix Ratio Results
Exact measurements for your herbicide solution
Enter your water volume and target weed type above, then click Calculate Mix to get the exact glyphosate measurements.
Glyphosate Mixing Quick Guide
Use this chart to quickly find out how much herbicide you need per gallon or liter of water based on the vegetation you are treating.
| Target Vegetation | Mix Percentage | Per Gallon (fl oz) | Per Liter (ml) |
|---|---|---|---|
| Annual Weeds / Grasses | 1% | 1.3 fl oz | 10 ml |
| Perennial Weeds | 2% | 2.6 fl oz | 20 ml |
| Tough Weeds / Vines | 3% | 3.8 fl oz | 30 ml |
| Heavy Brush / Woody | 5% | 6.4 fl oz | 50 ml |
Herbicide Mixing FAQ
Everything you need to know about mixing glyphosate safely, effectively, and protecting your garden environment.
The standard mixing ratio for glyphosate is typically a 1% to 2% solution for annual weeds and grasses, which equates to about 1.3 to 2.6 fluid ounces per US gallon of water. For perennial weeds and tough brush, a 3% to 5% solution (3.8 to 6.4 fl oz per gallon) is usually recommended. Always check your specific product label for exact instructions.
For a 25-gallon tank sprayer treating standard weeds (2% mix), you will need approximately 64 fluid ounces (half a gallon) of glyphosate. For heavy brush (5% mix), you would need about 160 fluid ounces (1.25 gallons). Always agitate the tank well before and during spraying.
Glyphosate needs time to become ‘rainfast’ and be absorbed by the plant foliage. Most standard formulations require 30 minutes to 3 hours of dry weather after application. If it rains heavily before this window passes, the herbicide may be washed off, reducing effectiveness. Check your specific product label for its rainfast period.
Glyphosate can often be tank-mixed with selective herbicides like 2,4-D or dicamba to broaden the spectrum of controlled weeds. However, you must always check both product labels for compatibility instructions, follow the most restrictive safety precautions, and perform a jar test to ensure the mixture doesn’t clump or separate.
Glyphosate is generally considered safe for pets and children once it has completely dried on the target foliage. However, while it is wet, it can be transferred through contact or ingestion. Keep pets and children out of the treated area during application and until the spray has fully dried to prevent any potential irritation or accidental ingestion.