Herbicide & Roundup per gallon calculator
Scale the ounces-per-gallon rate from your exact product label without guessing the formulation, use rate, or equipment.
There is no universal Roundup-per-gallon amount: products can use different active ingredients, rates, limits, and approved equipment. The current label for your exact product controls, including whether its rate is per gallon of water or per gallon of finished spray; those bases produce different amounts.
Scale the rate from your exact product label
Enter the rate exactly as printed and confirm what one gallon means. MixByParts scales the rate; it does not choose or recommend an application rate.
If the label gives ounces per acre or per 1,000 square feet, this volume-only calculator is not sufficient. Follow the label's carrier-volume, coverage, equipment and application limits.
Always follow the current label for your exact product and formulation. Roundup is a registered trademark of its owner; MixByParts is not affiliated with or endorsed by Roundup.
Popular use cases
- Scaling a label rate from one gallon of water to a larger water volume
- Calculating product and water for a specified finished-spray volume
- Converting an exact fl oz/gal label rate into metric amounts
Common mistakes
- Guessing from the Roundup brand name
Roundup products do not all use the same formulation, rate or equipment. Match the exact product and current label before entering a number.
- Missing the rate basis
“Per gallon of water” and “per gallon of finished spray” are different calculations. Select the wording that appears on the label and preserve it on the copied result.
- Treating an area rate as a volume rate
Ounces per acre or per 1,000 square feet cannot be scaled safely without calibrated coverage and carrier-volume information.
Finished-spray mathematical presets
Small finished-spray containers
These pages assume the stated product amount is contained within each finished gallon.
Metric finished-spray volumes
Mathematical conversions only; confirm that the label rate uses finished spray as its basis.
One-gallon finished batches
Exact volume splits for a one-gallon finished batch, not product recommendations.
Metric small batches
Finished-spray conversions for labels that explicitly use that basis.
Guides & resources
Why the exact current label controls where, how and how much pesticide may be used.
One current product with its own rates, active ingredients and equipment restrictions.
Penn State Extension walk-through on measuring output and matching label GPA.
University of Minnesota best practices for PPE, mixing order, and drift control.
Featured calculators
FAQs
How much Roundup should I add per gallon?
There is no single amount for every Roundup product. Find the rate on the current label for your exact formulation, enter that number, and select whether the label bases it on a gallon of water or a gallon of finished spray.
Why does the rate basis matter?
Adding product to one gallon of water creates more than one gallon of finished spray. A rate based on one finished gallon instead replaces some of that water with product. MixByParts keeps those instructions separate.
Can this calculator handle ounces per acre?
Not by itself. Area-based rates require the treated area, calibrated carrier volume, equipment output and every limit on the product label. Do not convert an ounces-per-acre instruction into a volume-only rate.