Bleach Dilution Calculator
Calculate the exact bleach and water volumes needed for a target chlorine concentration.
Inputs
Mixing result
Mixing plan
| Component | Volume | Share of final solution | Purpose |
|---|---|---|---|
| Bleach | 100 mL | 10.00% | Provides available chlorine |
| Water | 900 mL | 90.00% | Diluent |
| Total solution | 1 L | 100.00% | Target mixture |
How to use the bleach dilution calculator
What this calculator does. This tool estimates how much concentrated liquid chlorine bleach and how much water are needed to prepare a specified final volume at a lower chlorine concentration. It applies the standard dilution identity, so it is suitable for planning a liquid-to-liquid dilution when the label concentration and target concentration use compatible definitions. It does not determine whether a particular concentration is appropriate for a pathogen, surface, food-contact application, pool, drinking water, or medical setting. Those decisions must follow the bleach label and the relevant public-health guidance.
When to use it. Use it to scale a label-approved recipe to a different container size, prepare a laboratory or training example, compare a percent concentration with its ppm equivalent, or check the bleach-to-water ratio before measuring. For household disinfection, the CDC guidance for cleaning and disinfecting with bleach emphasizes following product directions, using room-temperature water, ensuring ventilation, and never mixing bleach with other cleaners.
How to calculate. The calculator opens with a complete demonstration: 5% bleach, a 0.5% target, and 1 liter of final solution. The example workbook is immediately available.
- Replace Bleach concentration with the sodium hypochlorite or available-chlorine concentration printed on the container. Select percent or ppm.
- Enter the Desired chlorine concentration in percent or ppm. It must be positive and lower than the stock concentration.
- Enter the Desired solution volume and select the unit you will actually measure.
- Read Required bleach volume and Water to add. The Bleach : water ratio is a convenient scaling guide, while Dilution factor shows how many times weaker the final solution is than the stock.
- Select Download Excel to save the current inputs and typed results as a validated workbook. Reset clears the demonstration and all calculated content; export remains unavailable until a complete valid state is entered again.
Input guide. Bleach concentration is required and accepts an ordinary decimal greater than zero, such as 5%, 8.25%, or 50,000 ppm. A percent value is converted internally using 1% = 10,000 ppm. Do not type both a symbol and a mismatched unit, and do not use scientific notation. Desired chlorine concentration is also required; an example is 0.5% or 5,000 ppm. Raising it increases the bleach volume and reduces the water volume. A target equal to or above the stock concentration cannot be produced by dilution. Desired solution volume is required and must be positive. It may be entered in milliliters, liters, teaspoons, tablespoons, US fluid ounces, cups, quarts, or gallons. Changing the volume scales bleach and water proportionally without changing the ratio.
Output guide. Required bleach volume is the measured stock-bleach volume. Water to add is the difference between final volume and bleach volume. Final volume repeats the requested total in a practical display unit. Bleach : water expresses one part bleach to the calculated number of water parts; a value of 1:9 means ten total parts. Dilution factor equals stock concentration divided by target concentration. The summary pills show the same dilution ratio, the bleach share of the final mixture, and the target concentration in ppm. The mixing-plan table lists each component, its volume, its share, and its role. These are mathematical estimates, not use recommendations.
Worked example. With 5% stock bleach, a 0.5% target, and a 1 L final volume, the formula gives V₁ = (0.5 ÷ 5) × 1 L = 0.1 L. Therefore, measure 100 mL of bleach and add 900 mL of water. Bleach is 10.00% of the final volume, the bleach-to-water ratio is 1:9, the dilution factor is 10×, and the target equals 5,000 ppm. These values match the first-open controls, result cards, table, and workbook.
Learn more. For occupational handling information, consult the NIOSH sodium hypochlorite safety entry. For emergency drinking-water situations, use the separate EPA emergency drinking-water disinfection instructions, because dose rules depend on bleach strength, water clarity, and waiting time.
Formula and safe interpretation
C₁ × V₁ = C₂ × V₂ → V₁ = (C₂ ÷ C₁) × V₂
The equation assumes that concentration is proportional to the amount of active chlorine and that volumes are additive. The required water is V₂ – V₁. Percent and ppm may be mixed because the calculator converts both to a common fraction before calculating. This is why 0.5% and 5,000 ppm produce the same result.
Freshly prepared diluted bleach can lose strength with time, heat, light, contamination, and unsuitable storage. Avoid making more than needed unless the product instructions support storage. For regulated disinfectant use in the United States, the label is legally controlling: concentration alone does not replace required contact time, pre-cleaning, rinsing, or surface restrictions.