Start with the exact product and intended use
“How much weedkiller per gallon?” is missing part of the question. The answer belongs to a particular product form, label and application.
Match the complete name, concentrate or ready-to-use form, registration number and source market. Then find the row for your intended use and equipment. A familiar brand name or similar bottle does not establish the same formulation or recipe.
HSE’s label guidance identifies the product’s registration, active ingredients, application conditions and limits as different pieces of information. The EPA’s introduction to labels likewise makes the label the place to establish how a product may be used.
A percentage is not a mixing instruction
An active-ingredient percentage describes what is in the supplied product. It does not, by itself, tell you how much product to add to a sprayer. An SDS describes hazards and handling; it does not supply a missing application label.
Read the noun after the quantity
The units are only part of a rate. Read what the quantity measures, then keep its application context attached.
- Product per water amount
- The reference quantity is water. Adding the product gives a larger nominal finished amount.
- Product per finished spray
- The product is included within the stated final quantity. A final fill mark and an amount of water are different starting points.
- Product per treated area
- The product amount is tied to ground area. Establish the allowed spray volume and calibrated coverage as well as the area to treat.
A source can mention more than one of these quantities. For example, the reviewed US Weed & Grass Killer₄ Concentrate page names water in its mixing instructions and spray solution in its coverage instructions. Keep both statements visible; do not silently replace one denominator with the other.
Keep the unit system attached too. US and Imperial gallons differ, and fluid ounces measure volume rather than weight. Our liquid label-rate calculator accepts US gallons and US fluid ounces, or metric mL and L.
Measured water and finished capacity are different
Five litres of measured water and five litres of finished spray are different targets. First establish the label’s denominator, then identify the amount you know.
Same fictional instruction.
Different starting quantity.
Arithmetic illustration only — not a dose for any weedkiller. Imagine an instruction expressly stating 10 mL product per 1 L of water. Choose what the number on your container represents.
Product
mLWater measured
LApproximate finished amount: 5.05 L. The product is added to the measured water, so the total exceeds that starting amount.
The fictional instruction’s denominator stays water in both cases. This changes the starting quantity, not the stated rate. Rounded display; nominal volumes assumed additive. This demonstration does not establish an allowed application, dose or mixing sequence.
For an expressly stated product-per-water rate, scale the product with the water quantity. When working back from a finished target, both components must fit within that target under the assumed volume model. Read the actual mixing sequence separately; arithmetic does not replace it.
Our label-rate calculator supports explicit liquid product-per-water and product-per-finished-spray quantities. It does not interpret an unclear percentage, weight instruction or area rate.
An area rate needs calibrated coverage
A five-litre tank is a capacity. It does not establish how many square metres you will treat with it. Equipment, nozzle settings and application technique affect the output over an area.
The Alberta government’s calibration guidance keeps product rate, application volume and treatment area separate. A water-only calibration can measure output for the intended setup; the actual product label must still permit that equipment, application and volume.
An area rate needs an area.
Fictional arithmetic, not a product instruction: assume a product amount of 20 mL per 100 m² and a chosen calibrated spray output. An actual product’s label must permit the application and spray volume; this example selects neither.
Product for 100 m²
mLFinished spray for 100 m²
L, including the productA 5 L finished tank would cover m² at this output. Prepare for the actual treatment area; tank capacity alone does not determine the batch you need.
At the same area and product-per-area rate, changing the permitted spray output changes the spray volume, while the product amount stays fixed. Real calibration uses the intended equipment and technique; water-only calibration measures output, not a product’s effectiveness or permission to change its label rate.
Keep product units and area units matched throughout. A product-per-hectare rate is not a product-per-litre rate. An area stated on a bottle can also be pack coverage, rather than the maximum dose for a single application.
The same product amount can use different water quantities
The reviewed SBK concentrate carton gives different water quantities for watering-can and sprayer treatment of the same weed area, while keeping the product amount fixed. Its stump instructions are separate again. The application row matters as much as the arithmetic.
Keep the preparation with its application
A tank sprayer, a hose-end jar, a ready-to-use bottle and a stump treatment are different contexts. A useful instruction summary must preserve those differences.
The reviewed US Roundup concentrate instructions give separate tank and hose-end preparation. Water delivered through the hose is not the same quantity as material placed in the jar. A dial setting or jar fill mark must stay with the specified equipment.
Ready-to-use describes the supplied product form. The reviewed US ready-to-use packet also describes refilling its bottle from a separate matching concentrate. That is a different product-and-container procedure; it does not make the supplied ready-to-use fluid a concentrate.
What stays attached to the mixing row?
Keep the target vegetation or situation, equipment, application method, coverage instructions, maximum dose, repeat-treatment limits and other label conditions with the selected row. Follow the complete applicable label, including its precautions, preparation and disposal instructions. This field guide explains quantities; it does not choose an authorised use or a suitable product.
What the instruction review found
The 2026 MixByParts Weedkiller Instructions Review examined twelve named product-form candidates in US and UK source contexts. The reviewed sources included a numeric treatment-area or coverage reference in eleven records. One selected concentrate name remains unresolved.
Quantities and contexts in the reviewed sources
12 selected records · overlapping categories
The evidence types also matter: six records use manufacturer-linked labels, three use regulator archive labels, two rely on manufacturer instruction pages, and one is unresolved. An archive’s contents are readable evidence of that edition, not proof that it is the applicable instruction for a current bottle.
6Manufacturer-linked label
3Regulator archive label
2Manufacturer instructions page
1Identity unresolved
Explore the source audit
Find the exact form and market, see what was coded, and open the original source. These are reading records, with limits retained, rather than a shortcut dose chart.
Roundup · USWeed & Grass Killer₄ ConcentrateRegulator archive label
Tank instructions name water as the mixing reference and spray solution as the coverage reference. Hose-end preparation is a separate context.
US manufacturer page and matching 2023 regulator archive reviewed. A master label contains optional wording and is not proof of the latest retail-container edition. Do not substitute an older glyphosate formulation or ignore equipment restrictions.
- Product form / identity
- Concentrate · EPA 71995-64
- Reviewed location
- Manufacturer page: tank / hose-end instructions. EPA PDF pp. 5–6: Mixing Instructions (printed pp. 4–5).
- Coded references
- Numeric water quantity · Numeric area or coverage · Rate or preparation variants
Roundup US exact concentrate instructionsUndated product page · Accessed 12 November 2026
EPA archive: LG1921 / Weed & Grass Killer₄ ConcentrateNotification accepted 5 June 2023; master-label context · Accessed 12 November 2026
Roundup · USWeed & Grass Killer₄, ready-to-use formManufacturer-linked label
Ready-to-use fluid is applied as supplied. The reviewed packet also states container coverage. Refilling its bottle from a separate concentrate is a distinct instruction.
Reviewed packet is the 24 fl oz form linked by the selected US product page. Its concentrate-refill directions do not turn ready-to-use fluid into a concentrate; those directions are not coded as a water-mixing instruction for this form.
- Product form / identity
- Ready to use · EPA 71995-65
- Reviewed location
- Manufacturer-linked packet: PDF p. 3, Product Facts / How to Apply; p. 4, How to Refill; p. 10, registration.
- Coded references
- Numeric area or coverage · Ready-to-use form
Roundup US ready-to-use productUndated product page · Accessed 12 November 2026
Manufacturer-linked ready-to-use label packetPPN 040161V0-27; no printed revision date established (©2022 is copyright) · Accessed 12 November 2026
Roundup · USDual Action Weed & Grass Killer Plus 4 Month Preventer ConcentrateManufacturer-linked label
Tank preparation names a water quantity and a separate coverage area. Directions also distinguish treating existing weeds from the surrounding prevention area.
This is the US 4 Month Preventer concentrate, not Dual Action 365 or a ready-to-use product. The page-linked label is artwork, not a demonstrated current approval inventory.
- Product form / identity
- Concentrate · EPA 71995-68
- Reviewed location
- Manufacturer-linked packet: PDF p. 5 (printed p. 2), Mixing Instructions; p. 15, registration.
- Coded references
- Numeric water quantity · Numeric area or coverage
Roundup US Dual Action 4 Month concentrateUndated product page · Accessed 12 November 2026
Manufacturer-linked Dual Action concentrate labelPPN 040165V2-03; no printed revision date established (©2022 is copyright) · Accessed 12 November 2026
Ortho · USWeed B Gon / WBG 553 Concentrate (archived US form)Regulator archive label
Northern and Southern lawn directions combine a product-per-water quantity with an area. Optional refill text describes filling to a final container mark.
Resolved to the archived 239-2744 form with listed Weed B Gon concentrate alternate names. This is not proof that a current retail bottle with a similar short name uses this formula. Bracketed master-label alternatives are not a universal container instruction.
- Product form / identity
- Concentrate · EPA 239-2744
- Reviewed location
- EPA PDF p. 11 (printed p. 10), How Much to Use / Apply; optional refill text on the same page.
- Coded references
- Numeric water quantity · Numeric area or coverage · Rate or preparation variants
EPA archive: WBG 553 ConcentrateNotification accepted 23 August 2023; annotated master-label context · Accessed 12 November 2026
Southern Ag · US2,4-D Amine Weed KillerManufacturer-linked label
The label contains area-based turf directions and a separate product-per-water spot-treatment section. A spot-treatment recipe must not be carried into a different application.
Reviewed the label linked from the exact Southern Ag product page. No printed revision date established. The SDS and upload-path year were not used to assign an application recipe or edition date.
- Product form / identity
- Concentrate · EPA 48273-4-829
- Reviewed location
- Manufacturer-linked label PDF p. 2: Lawns / ornamental turf, non-cropland and Spot Treatment of Weeds.
- Coded references
- Numeric water quantity · Numeric area or coverage · Rate or preparation variants
Southern Ag exact product and label linkUndated product page · Accessed 12 November 2026
Manufacturer-linked 2,4-D Amine labelNo printed revision date established · Accessed 12 November 2026
Gordon’s · USSpeedZone Lawn Weed Killer / 1381 EC Residential (historical form)Regulator archive label
Historical instructions separately name treatment area, water quantities and equipment-specific preparation. Filling a hose-end jar is not the same as establishing delivered spray volume.
Historical 2004 archive identifies SpeedZone Lawn Weed Killer as an alternate name. The modern SpeedZone EW product is a different identity and was not substituted. Current applicability of this historical form was not established; direct manufacturer-library requests were blocked.
- Product form / identity
- Concentrate · EPA 2217-864
- Reviewed location
- EPA archive PDF pp. 5–8: broadcast and spot treatment tables; hand-operated and hose-end sprayer instructions.
- Coded references
- Numeric water quantity · Numeric area or coverage · Rate or preparation variants
EPA archive: 1381 EC Residential / SpeedZone Lawn Weed KillerNotification dated 6 August 2004; historical reference only · Accessed 12 November 2026
Roundup · UKFast Action Total Weedkiller Concentrate — identity unresolvedIdentity unresolved
No exact application instruction was assigned to this selected name. A related ready-to-use product and a differently named concentrate cannot supply its recipe.
Retained in the fixed sample as unresolved. Total Optima Concentrate is a different named product and was excluded as a substitute. Absence from the reviewed sources does not prove discontinuation or authorisation status.
- Product form / identity
- Unresolved · Not established
- Reviewed location
- Public UK catalogue and a differently named Total Optima Concentrate page; no exact application label established.
- Coded references
- Unresolved — no application instruction assigned
UK catalogue — identity lead onlyUndated catalogue · Accessed 12 November 2026 · Excluded identity lead; not application evidence
Different Total Optima Concentrate — excluded candidateUndated product page · Accessed 12 November 2026 · Excluded identity lead; not application evidence
Roundup · UKFast Action Ready-to-Use WeedkillerManufacturer-linked label
The label identifies a ready-to-use solution with direct trigger-spray instructions. The corresponding manufacturer page separately gives a numeric pack coverage area.
Used the label actually linked by the UK 1 L page. A separately retrieved 3 L label was not substituted for its pack instructions. The ingredient concentration does not give a concentrate-mixing dose.
- Product form / identity
- Ready to use · MAPP 18679; PCS 01669
- Reviewed location
- Currently page-linked 1 L label: How to Use / composition. Product page: Coverage.
- Coded references
- Numeric area or coverage · Ready-to-use form
Roundup UK exact 1 L ready-to-use pageUndated product page · Accessed 12 November 2026
Manufacturer-linked 1 L Fast Action labelNo printed revision date established · Accessed 12 November 2026
Resolva · UKXtra Weedkiller ConcentrateManufacturer instructions page
The page links one product quantity to a water-volume range and a fixed treatment area. A permitted water range is not permission to change the product-per-area amount.
Only an SDS download was exposed. The preparation evidence is the manufacturer’s page, not an application label inferred from the SDS. A full container label remains necessary for the intended application.
- Product form / identity
- Concentrate · MAPP 19313 / PCS 06563 identified by linked SDS; application evidence is the page
- Reviewed location
- Manufacturer product page: How to Use; Important Information.
- Coded references
- Numeric water quantity · Numeric area or coverage
Westland Resolva Xtra instructionsUndated product page · Accessed 12 November 2026
Linked SDS — identity only, not an application labelSDS, not application instructions · Accessed 12 November 2026 · Identity only; not application evidence
Resolva · UKPro Xtra Tough Super Concentrate WeedkillerManufacturer instructions page
The table explicitly names product per litre of water, treated area and different annual / perennial weed contexts. Each row must stay with its use description.
Only an SDS download was exposed. The manufacturer page supplies the reviewed preparation instructions; the SDS is not used as an application label. Exact pack and market instructions remain controlling.
- Product form / identity
- Concentrate · No registration number established from the reviewed application page
- Reviewed location
- Manufacturer product page: How to Use, application table.
- Coded references
- Numeric water quantity · Numeric area or coverage · Rate or preparation variants
Westland Resolva Pro application tableUndated product page · Accessed 12 November 2026
Vitax · UKSBK Brushwood KillerManufacturer-linked label
The same weed-treatment area has different water quantities for the watering can and sprayer, while the product amount stays fixed. Stump applications are separate instructions.
The PDF has outlined lettering; its rendered page was visually inspected rather than treating an empty text extraction as missing instructions. No printed revision date established. Garden World is the Vitax manufacturer site; the carton names Vitax and that domain.
- Product form / identity
- Concentrate · MAPP 12711; PCS 03955
- Reviewed location
- Manufacturer-linked 250 mL carton, code 09086v10: How to Use, separate watering-can, sprayer and stump contexts.
- Coded references
- Numeric water quantity · Numeric area or coverage · Rate or preparation variants
Vitax Garden World exact concentrate pageUndated product page · Accessed 12 November 2026
Manufacturer-linked SBK concentrate cartonCarton code 09086v10; no printed revision date established · Accessed 12 November 2026
Weedol · UKLN Lawn Weed Control ConcentrateManufacturer-linked label
The label gives product, water and area together. The product form is explicitly concentrate on the linked carton.
The product page’s ingredient paragraph describes a ready-to-use solution despite its concentrate title. The linked concentrate label identifies the actual reviewed form and composition; that conflicting page paragraph was not used to establish a dilution recipe.
- Product form / identity
- Concentrate · MAPP 19314; PCS 06561
- Reviewed location
- Manufacturer-linked 1 L label: How to Use; maximum individual dose.
- Coded references
- Numeric water quantity · Numeric area or coverage
Weedol UK concentrate page and label linkUndated product page · Accessed 12 November 2026
Manufacturer-linked Weedol LN concentrate labelNo printed revision date established · Accessed 12 November 2026
These are instruction-reading records, not a dose chart. Manufacturer pages, archive labels and unresolved identities keep their different evidence roles. Check the full applicable container label for the exact product, application, equipment, market and restrictions.
How we reviewed the instructions
We fixed twelve named product-form candidates before detailed source coding: six US and six UK contexts, across seven brands. Selection was purposeful, to examine different ways quantities are expressed. It is not a representative market sample or an inventory of current authorisations.
What we coded
Explicit numeric water quantities, numeric treatment area or coverage, different numerical rate rows or preparation directions, ready-to-use form, source identity and evidence type. Site lists, pack sizes, coverage-only statements and refill recipes for another product form do not count as rate/preparation variants. Other categories record a reference in the source set, not an instruction for every use.
How we checked it
Manufacturer pages, linked labels and regulator archives retrieved on 12 November 2026. PDFs with raster or outlined text were checked visually. Multiple documents, pack sizes and application rows do not become extra products.
Evidence limits and unresolved fields
- The Roundup US concentrate archive is dated 2023. Ortho’s WBG 553 archive is also dated 2023 and contains alternate names and optional master-label text. Neither establishes the instruction on every similar-looking retail bottle.
- The SpeedZone record is the historical 2217-864 form in a 2004 regulator archive. Modern SpeedZone EW is a different identity and was excluded as a substitute. Direct manufacturer-library requests were blocked; current applicability was not established.
- The selected UK Fast Action Total Weedkiller Concentrate name could not be tied to an exact application label. It stays unresolved. The related ready-to-use form and differently named Total Optima concentrate do not fill that gap.
- Both Resolva records use the manufacturer’s public application pages. Their exposed downloads were SDS documents, not full application labels. The Xtra SDS supports identity only.
- The Weedol concentrate page contains a conflicting ready-to-use composition paragraph. The linked concentrate label, with its form and registration number, supplies the reviewed identity and preparation evidence.
- A copyright year, upload path or retrieval date is not a label revision date. Access does not establish current authorisation, market availability or applicability to a user’s product.
This is an AI-assisted source review, with coding checked against the retrieved instructions. We did not test efficacy, calibration accuracy, environmental outcomes or legal compliance. Unknown fields remain unknown. Source roles, links, edition notes and original-download hashes are retained in CSV and JSON; private analytics and manufacturer files are not republished.
Have an exact-label correction or a newer applicable source? Send the product, registration, market and edition.
Instruction identified?
Scale its liquid quantities.
Use the label-rate calculator when the liquid product and water or finished-spray reference are explicit. Area-rate interpretation and product selection remain separate.