Bleach Dilution Calculator
Determine how much bleach and water to mix to obtain a disinfecting solution at your desired strength.
Household bleach is typically 5–8% sodium hypochlorite.
Must be lower than the stock concentration.
Bleach volume
83.33 mL
Measure this amount of concentrated bleach.
Water volume
916.67 mL
Add water to reach the desired final volume.
Dilution factor: 12. This means the final solution is 12 times weaker than the stock bleach.
How to Use This Calculator
Check the stock label
Read the bleach bottle to find the sodium hypochlorite percentage. Enter that value as the stock concentration.
Pick your target strength
Enter the working concentration required (e.g., 0.5% for general disinfection).
Set the final volume
Choose how much solution you want to prepare. The calculator outputs the bleach and water amounts to mix.
Measure and mix safely
Wear gloves, measure bleach and water separately, then combine in a well-ventilated area.
Formula
C₁V₁ = C₂V₂
C₁ and V₁ are the stock concentration and volume. C₂ and V₂ are the desired concentration and final volume. Solve for V₁ to get the bleach volume and subtract from V₂ to find the water volume.
Example
To make 1 L of 0.5% solution from 6% bleach: V₁ = (0.5 × 1000) / 6 = 83.3 mL bleach. Add water to reach 1000 mL, so water volume ≈ 916.7 mL.
Full Description
Diluting bleach correctly ensures effective disinfection while minimizing safety risks. The classic C₁V₁ = C₂V₂ relationship scales concentrations and volumes to deliver the desired working solution.
Household bleach loses potency over time, so always verify stock concentration and prepare fresh solutions. Use appropriate protective equipment when handling concentrated bleach and avoid mixing with other chemicals.
This calculator aids custodial teams, healthcare workers, and homeowners who need quick, reliable dilution numbers without manual arithmetic.
Frequently Asked Questions
Can I use ounces or cups?
Yes. Enter the final volume in any unit, but keep bleach and water in the same unit as the final volume. The ratio remains the same.
How long is diluted bleach effective?
Prepare fresh solutions daily. Diluted bleach degrades rapidly, especially when exposed to light and heat.
What if my stock concentration is unknown?
Check the product label or manufacturer documentation. Without the stock concentration the calculation cannot be performed accurately.
Is tap water acceptable?
Yes, for household cleaning. Use sterile water for medical applications if required by protocol.
Can I scale the result?
Absolutely. Change the final volume to prepare larger or smaller batches while keeping the same target concentration.