How to Use the Bleach Dilution Calculator
The bleach dilution calculator tells you exactly how much bleach and water you need to mix to create a disinfectant solution of any desired concentration. Simply enter the total volume of solution you want to make, the concentration of your bleach bottle (commonly 5–6%), and choose your desired concentration from a preset use-case or enter a custom value in PPM or percent.
How to Dilute Bleach
The bleach dilution you need depends on its intended application:
- Food surface disinfection — approximately 200 ppm (about 1 tablespoon per gallon with 5% bleach)
- Non-food surface disinfection — approximately 1000 ppm
- Mold removal — approximately 5000 ppm (1 cup per gallon)
- Pool maintenance — 3.5–6 ppm (normal), 18 ppm (shock treatment)
- Emergency water disinfection — approximately 8 ppm
Bleach-to-Water Formula
The calculator uses the standard dilution equation C₁V₁ = C₂V₂:
- C₁ = concentration of bleach stock (e.g., 6%)
- V₁ = volume of bleach to add
- C₂ = desired concentration of the final solution
- V₂ = total volume of the final solution
Solving for bleach volume: V₁ = C₂ × V₂ / C₁
Water volume = Total volume − Bleach volume
Bleach Dilution Chart for Surface Disinfection
Recommended bleach type: unscented, 5–6% concentration. Always clean surfaces with hot water and soap first.
| Area / Item | Bleach amount | Water amount | ~ppm (at 5.25%) |
|---|---|---|---|
| Food contact surfaces | 1 tbsp (15 mL) | 1 gallon (3.8 L) | ~200 ppm |
| Non-food surfaces | 1 cup (240 mL) | 5 gallons (18.9 L) | ~660 ppm |
| Mold growth | 1 cup (240 mL) | 1 gallon (3.8 L) | ~3300 ppm |
Pool Disinfection
Use your chlorine bleach daily. Use bleach stabilizer (cyanuric acid) once a month at 45 mg/L.
| Level | Concentration |
|---|---|
| Minimum | 3.5 ppm |
| Target | 6 ppm |
| Shock level | 18 ppm |
Emergency Drinking Water Disinfection
Using 1% bleach: add 10 drops per liter (40 drops per gallon). Let stand 30 minutes before drinking. If water is cloudy, double the amount. Using 5–6% bleach: add 2 drops per liter (8 drops per gallon).
Units Supported
The calculator supports both US customary units (gallons, quarts, pints, cups, fluid ounces, tablespoons) and metric units (liters, milliliters). Results are shown in both systems for your convenience.
Safety Precautions
- ⚠️ Never mix bleach with ammonia, vinegar, other cleaners, or acids — toxic gases may form
- Always add bleach to water, not water to bleach
- Work in a well-ventilated area — avoid inhaling bleach fumes
- Wear gloves, protective clothing, and goggles
- Read and follow the instructions on your product label
- Store diluted bleach in a sealed, labeled container
- Use diluted bleach solutions within 24 hours — they lose effectiveness over time
Source: CDC guidelines on disinfection with household bleach. For pool chemistry: TroubleFreePool recommendations.