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Spray dilution calculator — pesticide and plant protection products
Enter the product concentration and the working concentration from the label, and the calculator will give you the exact amount of product and water needed. Two modes are supported: calculating water volume for a given amount of concentrate, and calculating product volume for a given tank capacity. Results are indicative — always follow the product label.
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How we calculate
Mode 1 (working solution): total volume [L] = (ml of concentrate × product conc. %) / (working conc. % × 1000); water [L] = total volume − ml of concentrate / 1000. Mode 2 (amount of product): product [ml] = water volume [L] × 1000 × working conc. % / product conc. %. Consumption = ml of product / total liquid volume.
Example: 20% fungicide, working concentration 0.5%, 10 L tank
Mode 1 (how much water): 50 ml of 20% concentrate at 0.5% working strength → total volume = 50 × 20 / (0.5 × 1000) = 2 L; water = 2 − 0.05 = 1.95 L. Mode 2 (how much product): 10 L of water, 20% product, 0.5% working strength → product = 10 × 1000 × 0.5 / 20 = 250 ml. Consumption: 25 ml/L.
Frequently asked questions about spraying and dilution
What is the working concentration of a spray solution?
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.
How do I calculate how much pesticide to add to my sprayer?
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.
How much water do I need to dilute a concentrate?
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.
Can I use a lower concentration for safety?
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.
What do EC, WP, and WG mean on a plant protection product?
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.
How do I safely prepare a spray solution?
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).
How many ml of product per litre of water?
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.
How do I calculate the amount of product for a whole garden?
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.
What is the difference between a fungicide, insecticide, and herbicide?
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.
How do I dispose of leftover spray solution?
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.
Results are indicative — always follow the product label. Incorrect concentration may damage plants or reduce effectiveness. Comply with all regulations on the use of plant protection products.
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