Insecticidal Soap Dilution & Mixing Calculator
Tell it the container you actually own and the plant you want to treat. It scales our published soap-spray recipes to exact measurements — and warns you first if your plant shouldn’t be sprayed at all.
1. Container size
2. Soap type
Dawn is a detergent, not true soap. We recommend it only for occasional, one-time use on hardy, non-edible plants — not repeat treatments or edibles. Use Dawn Original (blue bottle) only. For regular spraying, switch to castile soap.
3. Plant sensitivity
Tiers come from our Plants Sensitive to Insecticidal Soap guide. Not sure? Patch-test first.
4. Optional boosters
Every batch, every time
- Patch-test first. Spray 2–3 leaves and wait 24–48 hours before treating the whole plant.
- Never in hot sun. Apply in early morning or evening, and not when it’s hotter than ~85–90°F.
- Coat both sides. Spray leaf tops and undersides until just dripping — pests cluster underneath.
- Reapply every 4–7 days. Soap has no residual effect once it dries.
- Use distilled or rainwater where you can — hard tap water reduces effectiveness. Mix gently to keep foam down.
How the math works
This tool does not invent anything. It only scales the ratios we already publish, using standard US measures (1 tbsp = 3 tsp ≈ 14.8 mL; 1 tsp ≈ 4.93 mL). Every number traces to one of our recipes:
- Castile soap: 1 tbsp per quart (~1.5%, ceiling 2%) — Basic Castile Soap Spray
- Dawn Original: 1 tsp per quart, occasional use only — Dawn Dish Soap Spray
- Neem oil booster: 1 tsp per quart — Neem Oil Insecticidal Soap
- Essential oil booster: 10–15 drops per quart, max 15 — Essential Oil Spray
- Plant sensitivity tiers — Plants Sensitive to Insecticidal Soap
Amounts are guidance for home use, not a prescription. When in doubt, mix weaker and patch-test.