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Roundup Mix Calculator: The Right Oz Per Gallon for Your Exact Product

"How much Roundup per gallon" has no single answer — the consumer lineup spans 18% to 50% glyphosate, so the correct dose ranges from 1.5 to 6 oz per gallon depending on which bottle you're holding. Mixing Super Concentrate at a Concentrate Plus rate quadruples your cost; the reverse under-doses and lets weeds regrow from the roots. Pick your product below, enter your tank size, and get the exact amount.

Not sure which Roundup you have? The product name is on the front label — the word "Concentrate" alone isn't enough. Generic 41% glyphosate (Ranger Pro, Compare-N-Save, etc.) mixes differently — use the Glyphosate 41% Calculator for those.

Mixing a different herbicide? Herbicide Mixing Calculator · 2,4-D · RM43

Calculator

Roundup Concentrate Calculator

Product + tank size → exact concentrate amount with household measures.

Measure it, don't eyeball it — a measuring syringe↗ pays for itself in one tank of Super Concentrate.

The Roundup concentrate lineup — same brand, four different chemistries

The brand name hides real differences in what's in the bottle, and the mixing rate follows the chemistry:

Product Actives Oz per gallon Best for
Super Concentrate 50.2% glyphosate 1.5 Large areas, best cost per gallon of spray
Concentrate Plus 18% glyphosate + diquat 3 (6 for tough weeds) Fast visible results on ordinary weeds
Extended Control Conc. Glyphosate + imazapic 6 Driveways, gravel — months of bare ground
Poison Ivy + Tough Brush Glyphosate + triclopyr 6 Woody vines, brush, poison ivy/oak

Rates are common label directions — the label on your bottle is the law and supersedes this table. Formulations change between product years; check yours.

The two ingredients that change everything

Diquat (Concentrate Plus) is a contact burner: leaves brown within hours, which feels satisfying but adds nothing systemic — the glyphosate still does the root-kill on its own timeline. Imazapic (Extended Control) is the one to respect: it stays active in soil for months, which is the entire point on a gravel driveway and a disaster in a bed you meant to replant. If your treated area should ever grow anything again, Extended Control is the wrong bottle — and for full bare-ground programs, compare it against RM43, which does the same job at a different price point.

Ready-to-use vs concentrate: the arithmetic

A quart (32 oz) of Super Concentrate at 1.5 oz/gal mixes about 21 gallons of spray. Buying the same 21 gallons as ready-to-use jugs means paying herbicide prices for water, roughly 20 times over — plus 21 trigger-sprayer hand cramps. The break-even is fast: if you spray more than two or three gallons a season, a pump sprayer↗ plus concentrate wins, and for regular property maintenance a backpack sprayer↗ turns it into a walk. RTU earns its price only for a handful of driveway cracks a year.

Mixing order and clean-out

Fill half the water, add the measured concentrate, then top up while the tank agitates — concentrate poured onto a dry tank bottom is what clogs filters. Spray mixed product the same day; glyphosate loses activity sitting mixed in hard water. And if the sprayer's next job is anything you want to keep alive, run a tank cleaner↗ through it first.

FAQ

How much Roundup concentrate do I mix per gallon of water?

Depends on the product: Super Concentrate ≈ 1.5 oz/gal, Concentrate Plus 3–6 oz/gal, Extended Control and Poison Ivy Plus ≈ 6 oz/gal. The calculator handles all four for any tank size.

Why do different Roundup products have different mixing rates?

Different chemistry under one brand: glyphosate concentration ranges from 18% to 50.2%, and some products add diquat, imazapic, or triclopyr. See the lineup table.

Is Roundup concentrate cheaper than ready-to-use?

Roughly 20× cheaper per gallon of spray once you own a sprayer — a quart of Super Concentrate mixes ~21 gallons. The math above.

What's the difference between Concentrate Plus and Super Concentrate?

Concentrate Plus: less glyphosate plus diquat for fast browning. Super Concentrate: 50.2% glyphosate, slower visuals, more killing power per dollar. Big jobs and tough perennials favor Super Concentrate.

Should I use Extended Control near plants I want to keep?

No — its imazapic residual keeps soil bare for months. Bare-ground areas only, outside the root zones of anything you value.

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Important note

This page describes common label directions for identification and planning. The label on your bottle is the legal document — follow its rates, sites, and precautions, including re-entry and rainfast intervals. Wear label-required PPE such as chemical-resistant gloves↗. Affiliate links support the site at no extra cost to you.