Bleach Dilution Calculator for Sanitizing and Disinfecting
Enter your bleach's strength and the ppm you need to get exact amounts, or check the strength of a mix you already use.
Calculated on your device
Household bleach is usually between 3% and 8.25%.
Add 3.33 mL of bleach to 0.997 L of room-temperature water.
You'll have 1 L of solution at about 200 ppm (0.02%).
With measuring spoons: about 0.68 tsp of bleach.
Results are a guide. Check them against your procedures and product labels before you rely on them.
Safety first
- Never mix bleach with ammonia, vinegar, acids or other cleaners. It releases toxic gases.
- Use plain, unscented bleach and follow the directions on its label. Some bleach products aren't meant for disinfecting or for food areas.
- Mix with cold or room-temperature water in a well-ventilated place. Wear gloves and protect your eyes.
- Clean off dirt first. Bleach doesn't work well on dirty surfaces.
- Make a fresh solution every day. It loses strength over time, especially in sunlight.
- Keep bleach and bleach solutions in labeled containers, out of reach of children.
How to use the bleach calculator
- 1Find the percentage of sodium hypochlorite on your bleach's label and enter it.
- 2Enter the strength you want, in ppm or %, or pick a common one. Then enter how much solution you want to make.
- 3Measure the bleach, add it to the water, and stir. To check a recipe you already use, choose "How strong my mix is" instead.
Choosing the right strength
Bleach is sold in different strengths, so a recipe written for one product can be too weak or too strong with another. The active ingredient is sodium hypochlorite, and the label shows how much of it the bleach contains as a percentage. This calculator starts from that number.
For sanitizing food-contact surfaces such as dishes, utensils and worktops, food-safety codes like the US FDA Food Code call for about 50 to 100 ppm of chlorine, and US rules allow up to 200 ppm without rinsing. For disinfecting surfaces at home, the US CDC recommends 5 tablespoons (⅓ cup) of household bleach per gallon of water, which is about 1,000 ppm. Stronger solutions, up to 5,000 ppm, are often recommended for spills of blood or body fluids. Local rules and your product's label come first.
Labels give the percentage by weight, while test strips measure what's called available chlorine. This calculator treats the label percentage as grams per 100 mL, which is accurate to within about 10%. That's close enough for everyday cleaning. Where you must stay within a set range, such as in a food business, check the solution with chlorine test strips.
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Frequently asked questions
How much bleach per gallon of water makes 200 ppm?
With 6% bleach, about 2½ teaspoons (13 mL) per gallon. With 8.25% bleach, about 2 teaspoons (9 mL), and with 5.25% bleach, about 3 teaspoons (1 tablespoon). Enter your bleach's strength above for an exact amount.
How many ppm is 1 tablespoon of bleach per gallon?
About 230 ppm with 6% bleach, 200 ppm with 5.25% bleach and 320 ppm with 8.25% bleach. Choose "How strong my mix is" to check any recipe.
How much bleach per liter makes a 0.1% (1,000 ppm) solution?
About 17 mL of 6% bleach, or 20 mL of 5% bleach, made up to 1 liter with water.
Can I use this to disinfect drinking water?
No. Drinking water needs far weaker doses and its own instructions. Follow the guidance of your local health authority.
Is what I type sent anywhere?
No. The calculation happens in your web browser, on your own device. Nothing you enter is sent to us or anyone else.
Is it free?
Yes. There is no sign-up and no limit on how often you use it.
Does it work on my phone?
Yes. It works in any modern browser on Android, iPhone, iPad, Windows, Mac and Linux.