Bleach Dilution Calculator

Our handy bleach dilution calculator is designed to help users determine the correct proportions of bleach and water for various disinfecting purposes.

Suppose you need to create a 0.1% sodium hypochlorite solution using household bleach with 5.25% concentration. The calculator helps determine that you need to mix 1 part bleach with 51 parts water. This means for every 1 mL of bleach, you’d add 51 mL of water.

Initial Concentration	Desired Concentration	Total Volume	Bleach Volume	Water Volume
5.25%	0.05%	2000 mL	19.05 mL	1980.95 mL
8.25%	0.1%	1500 mL	18.18 mL	1481.82 mL
6%	0.5%	3000 mL	250 mL	2750 mL
5.25%	1%	500 mL	95.24 mL	404.76 mL
5%	10 ppm	1 gallon (3.8 L)	2/3 cup (160 mL)	3.8 L – 160 mL = 3.64 L
6%	25 ppm	1 gallon (3.8 L)	1/3 cup (80 mL)	3.8 L – 80 mL = 3.72 L
5.25%	100 ppm	1 liter (1000 mL)	19 mL	981 mL
8.25%	50 ppm	1 liter (1000 mL)	12.12 mL	987.88 mL
5%	200 ppm	500 mL	50 mL	450 mL
6%	150 ppm	2 liters (2000 mL)	100 mL	1900 mL
5.25%	500 ppm	1 liter (1000 mL)	38.46 mL	961.54 mL
8.25%	300 ppm	1 liter (1000 mL)	36.36 mL	963.64 mL

Bleach Dilution Ratio Chart

Desired Concentration	Bleach (5.25%)	Water
0.05%	1 part	104 parts
0.1%	1 part	51 parts
0.5%	1 part	9 parts
1%	1 part	4 parts
2%	1 part	1.6 parts

Bleach Dilution Formula

The bleach dilution formula is:

C1 * V1 = C2 * V2

Where:

C1 = Initial concentration of bleach
V1 = Volume of bleach to be added
C2 = Desired final concentration
V2 = Total volume of solution

To determine the volume of bleach needed:

V1 = (C2 * V2) / C1

Example

Let’s say you want to create 1 liter of a 0.1% solution using 5.25% bleach.

V1 = (0.1% * 1000 mL) / 5.25% = 19.05 mL

You’d need to add 19.05 mL of 5.25% bleach to 980.95 mL of water to create 1 liter of a 0.1% solution.

How to Calculate Bleach Dilution?

Calculating bleach dilution involves several steps:

Determine the desired concentration based on your application.
Identify the concentration of your bleach (usually stated on the bottle).
Decide on the total volume of solution you need.
Apply the dilution formula to calculate the required amount of bleach.
Subtract the bleach volume from the total volume to get the water amount.

Creating 2 liters of a 0.5% solution using 8.25% bleach:

Desired concentration: 0.5%
Bleach concentration: 8.25%
Total volume: 2000 mL
V1 = (0.5% * 2000 mL) / 8.25% = 121.21 mL
Water needed: 2000 mL – 121.21 mL = 1878.79 mL

Mix 121.21 mL of 8.25% bleach with 1878.79 mL of water.

How Much Bleach to 1 Liter of Water for Disinfecting?

For general disinfection (0.1% solution) using 5.25% bleach:

Required bleach = (0.1 × 1000) ÷ 5.25 = 19mL
Add to 981mL water

The amount of bleach needed for 1 liter of water depends on the desired concentration and the initial bleach strength.

Using 5.25% bleach to create 1 liter of a 0.1% solution:

V1 = (0.1% * 1000 mL) / 5.25% = 19.05 mL

Add 19.05 mL of 5.25% bleach to 980.95 mL of water.

What is the Ratio of Bleach to Water for Disinfecting?

Standard disinfecting ratios:

Light disinfection (0.05%): 1:100
Standard disinfection (0.1%): 1:50
Heavy-duty disinfection (0.5%): 1:10

For general household disinfecting, a common ratio is 1:50 (1 part bleach to 50 parts water), which creates approximately a 0.1% solution when using 5.25% bleach.

To make 500 mL of solution with a 1:50 ratio:

Bleach: 500 mL / 51 ≈ 9.8 mL
Water: 500 mL – 9.8 mL = 490.2 mL

How Much Bleach to Add to a 32 oz Spray Bottle?

To determine the amount of bleach for a 32 oz (946 mL) spray bottle, consider the desired concentration. For a 0.1% solution using 5.25% bleach:

V1 = (0.1% * 946 mL) / 5.25% = 18 mL

Add 18 mL of 5.25% bleach to 928 mL of water in the spray bottle.

What is a 1:20 Dilution of Bleach?

A 1:20 dilution means 1 part bleach is mixed with 19 parts water, creating a total of 20 parts. This ratio typically results in a solution with about 0.25% concentration when using 5.25% bleach.

To create 1 liter of a 1:20 dilution:

Bleach: 1000 mL / 20 = 50 mL

Water: 1000 mL – 50 mL = 950 mL

Mix 50 mL of 5.25% bleach with 950 mL* of water.

Sources / References

Environmental Protection Agency (EPA) – List N Tool: COVID-19 Disinfectants: https://cfpub.epa.gov/wizards/disinfectants/

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Bleach Dilution Calculator – Proper Bleach Dilution for Cleaning and Disinfection