Chemistry

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Bleach Dilution Calculator.

Calculate stock bleach and water volumes using C1V1 = C2V2.

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Set your values

Results update as you type.

Stock volume: 100 volume units

Stock volume

100.000000volume units
Water volume: 900 volume units

Water volume

900.000000volume units

Educational formula calculator. Keep units consistent; chemistry procedures, concentrations, and safety decisions require qualified laboratory guidance. Never mix cleaning products.

Use Cases

Preparing disinfecting solutions

Calculate how much bleach to mix with water to achieve a specific concentration for cleaning and disinfecting surfaces, such as a 0.1% solution.

Example: Make 1 liter of 0.1% bleach from 5.25% stock: need 19 mL bleach and 981 mL water.

Diluting concentrated bleach for laundry

Determine the correct amount of concentrated bleach to add to a wash load to reach a safe and effective concentration.

Example: For a 0.05% final concentration in 10 gallons, use about 3.8 oz of 8.25% bleach.

Frequently Asked Questions

How does the bleach dilution calculator work?
It uses the formula C1V1 = C2V2, where C1 is the stock concentration, V1 is the stock volume needed, C2 is the final concentration, and V2 is the final volume. Enter the stock concentration, final concentration, and final volume to get the required stock bleach volume and water volume.
What units should I use for the final volume?
You can use any volume unit (e.g., mL, L, gallons) as long as you use the same unit for the final volume. The calculator will output the stock bleach volume and water volume in that same unit.
Can I use this calculator for any bleach concentration?
Yes, as long as you know the stock concentration (in %) and the desired final concentration (in %). It works for any household bleach solution, such as 5.25% or 8.25% sodium hypochlorite.

Tips & Common Mistakes

Tips

  • Always add bleach to water, not water to bleach, to avoid splashing and fumes.
  • Use the same volume unit for the final volume and the calculated stock volume (e.g., mL, L, gallons).
  • Check the label of your bleach for its actual concentration, as it can vary (e.g., 5.25%, 6%, 8.25%).
  • Prepare fresh bleach solutions daily, as bleach degrades over time.

Common Mistakes to Avoid

  • Using different units for the final volume and the stock volume, leading to incorrect ratios.
  • Forgetting to convert percentages to decimals when doing manual calculations, but this calculator handles it automatically.
  • Assuming all bleach has the same concentration; always verify the stock concentration.

Last updated: August 13, 2026