H2O2 Mixing Chart:
Diluting 12% hydrogen peroxide to make 3% hydrogen peroxide

Mixing 12% hydrogen peroxide to get 3% hydrogen peroxide

Are you looking for a H2O2 mixing chart to dilute 12% H2O2 with water, to get 3% H2O2?  You've come to the right place....

To make 3% hydrogen peroxide from 12% hydrogen peroxide, the general mixing guideline is: 1 part 12% hydrogen peroxide plus 3 parts water = 3% hydrogen peroxide. You can use this guideline with any quantity you need to mix.

To make a gallon of 3% peroxide: In a clean gallon container, combine 4 cups of 12% food grade hydrogen peroxide with 12 cups of water. That makes a gallon of 3% hydrogen peroxide.


H2O2 Mixing chart for mixing 12% hydrogen peroxide with water to get 3% hydrogen peroxide

Here’s the same thing I just said, but in the form of a H2O2 mixing chart:

USE THIS AMOUNT OF 12% HYDROGEN PEROXIDE AND THIS AMOUNT OF WATER* TO MAKE THIS AMOUNT OF 3% HYDROGEN PEROXIDE
1 part 3 parts 4 parts
1/4 cup 3/4 cup 1 cup
1 cup 3 cups 4 cups
4 cups 12 cups 1 gallon (16 cups)


More “how-to” details, and how to make it easier to do…..

To make measuring and mixing a gallon of 3% peroxide easier, do this:

  • Make a gallon of 3% hydrogen peroxide, as described above, by mixing 4 cups of 12% food grade hydrogen peroxide with 12 cups of water. Measure it out.
  • Use a permanent marker to make a mark on the outside of the bottle, where the level of the gallon of liquid fills the bottle up to.
  • The next time you want to dilute 12% peroxide to make 3% peroxide, you can use your empty bottle like this: measure 4 cups of 12% hydrogen peroxide, and pour it into the empty bottle. Then add enough water to fill up the bottle, up to the line that's you made that shows where 16 cups fills to.

This eliminates having to measure and count out 12 cups of water each time!


Please Always Label the % on All Containers of Peroxide

When you make 3% hydrogen peroxide from 12%, PLEASE PLEASE be sure to label every container with so you know what's what.

The label should say HYDROGEN PEROXIDE.

And the concentration: like 3% or 1% or 12%.

This is super important. It can be DANGEROUS if you don't know what concentration you are using. So please please do it.

ALWAYS label all containers clearly, including the concentration (also called percentage or strength).


You’ll find more hydrogen peroxide dilution charts here: You’ll find more about concentrations of hydrogen peroxide and dilutions here:


* What kind of WATER?

In the hydrogen peroxide dilution chart, above, I just say “water”. But what kind of water?

That will depend on what you are planning to use the peroxide for. For most purposes, tap water will work.

Here is the exception: If you plan to use the peroxide as an oxygen supplement – to be ingested by anyone (including animals) – then you should consider using distilled water, or filtered water, if at all possible.

Any metals in water will combine with hydrogen peroxide. I’ve read that this is bad stuff to ingest. I’d like to know a lot more than I do about why, and what the level of risk is. I can’t add a lot to this, other than to say that I’ve read that this is risky. How risky I don’t know. But it does make some sense: peroxide is an oxidant. Oxidizing metal creates rust. Drinking rust particles doesn’t seem like a good idea.

I’ve also read that it is bad to ingest peroxide in combination with iron supplements. The reason is the same: iron is a metal.

If you plan to ingest peroxide, you can consider this.


Return from H2O2 Mixing chart for diluting 12% to 3% to how to dilute hydrogen peroxide...


Subscribe to Hydrogen Peroxide Explorers' Newsletter

Our newsletter will keep you up to date on new pages added, plus some Adventures you can try at home:

No worries! Your email will be used ONLY to send you newsletters.

Food Grade 3% Hydrogen Peroxide (Quart):

Food Grade 12% Hydrogen Peroxide
(2 Gallons):

Sodium Percarbonate
(5 pounds):

For some links, I receive ad commissions, at no cost to you. More info here.




Site Search:



Subscribe to our newsletter (free):



Note: Products shown are sold by Amazon. This site does NOT sell hydrogen peroxide.



Do you like this site?



[?]Subscribe To This Site
  • XML RSS
  • follow us in feedly
  • Add to My Yahoo!



garden sprayer for use with hydrogen peroxide

Gardening: attach sprayer to garden hose; use to dilute peroxide and spray on the garden

spray bottles for peroxide

Spray bottles for peroxide