Spray dilution calculator — pesticide and plant protection products

The working concentration is the percentage of active ingredient in the ready-to-use spray solution. It is stated on the product label, for example as 0.2% or 0.5%. Typical working concentrations range from 0.1% to 2% depending on the type of product and target pest or disease.

Use the formula: product (ml) = tank volume (L) × 1000 × working concentration (%) / product concentration (%). For example, a 20% product at 0.5% working strength: 10 L × 1000 × 0.5 / 20 = 250 ml. The calculator does this automatically.

Water volume (L) = (ml of concentrate × product concentration / working concentration / 1000) − ml of concentrate / 1000. Enter the amount of concentrate and the concentrations into the calculator and it will work out the water volume instantly.

It is not advisable to reduce the concentration on your own. Too low a concentration may be insufficient to control the pest or disease, wasting the product. Always use the rate recommended by the manufacturer on the label.

EC (Emulsifiable Concentrate) — a liquid concentrate that forms an emulsion with water; WP (Wettable Powder) — a powder that forms a suspension; WG (Water-Dispersible Granule) — granules that disperse in water. All are diluted with water. The concentration stated on the label accounts for the formulation type.

Wear personal protective equipment (gloves, goggles, mask). Half-fill the sprayer with water, add the measured product, then top up with water while mixing. Spray in calm conditions (wind below 4 m/s), preferably in the morning or evening. Observe the pre-harvest interval (PHI).

It depends on the product concentration and the recommended working strength. Formula: ml/L = 1000 × working conc. (%) / product conc. (%). For a 20% product at 0.5% working strength: 1000 × 0.5 / 20 = 25 ml/L.

Calculate your garden area (m²), check the liquid application rate from the label (usually 100–600 L/ha = 10–60 L per 1000 m²), calculate the total liquid volume needed, then use the calculator to find the product amount. The calculator helps with the dilution step.

A fungicide controls fungal diseases (mould, mildew, rust). An insecticide targets insects and other invertebrate pests. A herbicide kills or suppresses weeds. All are plant protection products and must be diluted according to label instructions.

Never pour leftover spray solution down the drain or into water. Apply it to the treated crop at the diluted working strength (do not exceed the label rate). Rinse the sprayer three times, applying rinsings to the crop. Dispose of empty containers according to local regulations.