Pesticide Dilution Calculator
Calculate how much pesticide concentrate and water you need to prepare a diluted spray solution based on the desired concentration or dilution ratio.
Enter X — the number of parts water per 1 part concentrate.
Formulas Used
Dilution Ratio Mode (1 : X)
Concentrate Volume = Total Volume × 1 / (X + 1)
Water Volume = Total Volume − Concentrate Volume
Percentage Mode
Concentrate Volume = Total Volume × (Target% / 100)
Water Volume = Total Volume − Concentrate Volume
PPM Mode
Concentrate Volume = (Target ppm × Total Volume) / (Stock Concentration% / 100 × 1,000,000)
Water Volume = Total Volume − Concentrate Volume
Concentration Conversions
ppm = (Concentrate Volume / Total Volume) × Stock Fraction × 1,000,000
% = (Concentrate Volume / Total Volume) × 100
Assumptions & References
- Assumes the concentrate and water have the same density (approximately 1 kg/L), which is valid for most aqueous pesticide formulations.
- Dilution ratio 1:X means 1 part concentrate to X parts water, giving a total of (X+1) parts solution.
- PPM calculations assume the stock concentration refers to the active ingredient fraction by volume.
- Volume unit conversions: 1 US gallon = 3.78541 L; 1 US quart = 0.946353 L.
- Always follow the pesticide label instructions — label directions supersede any calculated values.
- Reference: EPA pesticide label requirements (40 CFR Part 156); WHO Pesticide Evaluation Scheme (WHOPES) guidelines.
- For emulsifiable concentrates (EC) or wettable powders (WP), consult the product Safety Data Sheet (SDS) for density corrections.