Adjuvant / Surfactant Rate Calculator
Calculate how much adjuvant (surfactant/sticker) to add to a spray tank as a percentage of spray volume.
Adjuvants (surfactants, stickers, spreaders) are usually added at 0.1–0.5% of spray volume. They improve coverage and rainfastness, but over-dosing can cause runoff or leaf burn. Add the adjuvant last, after the other products are mixed.
Always follow the product label — the label is the law. Verify doses, PHI and compatibility with the manufacturer and local regulations before spraying.
Spray operators and farmers use the free Adjuvant / Surfactant Rate Calculator for an accurate answer in seconds — no formulas to remember, works offline in the field.
About Adjuvant / Surfactant Rate Calculator
Adjuvants — surfactants, spreaders and stickers — make a spray wet the leaf evenly, resist rain and penetrate better, often making the difference between a spray that works and one that beads off. They're added at a small percentage of spray volume (typically 0.1–0.5%), and over-dosing causes runoff or scorch. This tool gives the exact millilitres to add to your tank, which should always go in last after the main products are mixed.
How to use Adjuvant / Surfactant Rate Calculator
- 1Enter your sprayer/field values into the inputs.
- 2Read the headline result and the supporting breakdown.
- 3Apply the guidance in the note to your spraying.
Why use Adjuvant / Surfactant Rate Calculator?
- ✓Uses the standard, citable spray-calibration formula
- ✓Clear inputs with sensible defaults
- ✓Instant result with the working shown
- ✓Free, fully in-browser and private
Frequently asked questions
How much surfactant do I add to a spray tank?+
Usually 0.1–0.5% of the spray volume, per the adjuvant label — about 15–75 ml in a 15-litre tank. This tool gives the exact amount; add it last, after the pesticide is mixed, to avoid excessive foaming.
Do I always need an adjuvant?+
Not always — many formulated products already contain surfactants. Add one when the label recommends it, when spraying waxy or hairy leaves that water beads off, or for systemic herbicides where uptake matters. Avoid over-dosing, which causes runoff.
Is this tool free and private?+
Yes — free, no sign-up, and all calculation runs in your browser, so it works offline in the field and your data never leaves the device.
Related Agri tools
Tractor Fuel Consumption Calculator
Estimate your tractor's diesel consumption per hour from its horsepower, load and specific fuel consumption.
● LiveTractor Fuel Cost Per Acre Calculator
Convert your tractor's fuel use per hour into diesel litres and cost per acre for any field operation.
● LiveImplement Field Capacity Calculator
Calculate the effective field capacity (ha/h and acres/h) of any implement from width, speed and field efficiency.
● Live