Converting a recipe from percentages to ounces


Many times you run across recipes that are written in percentages. These are great because you can convert them into workable recipes for any size of mold or production.

Sometimes the process of converting percentages to the recipe size that you need can be confusing. Let’s walk through it.–P5199.aspx?afid=5
I’ve got this nifty silicone mold from Bramble Berry. After checking out the website I see that it holds 50 oz of soap and measures 10″ x 3 5/8″ x 2.25″. Before I convert my recipe from percentages to ounces…I need to know the amount of oil that it holds.

50 oz of soap means it holds 50 oz of finished soap (water + lye+ oils). I need to know how much oil it will hold so I can convert my percentages to ounces of oils.

I use the formula l (length) x w (width) x h (height) x .4 to determine how many ounces of oil my recipe needs to be.

So for the BB loaf mold:
10 x 3.625 x 2.25 x .4 = 32.625 oz

I like to do fluffy tops so I will add about 4 extra ounces so I have enough soap on top.

My recipe needs to contain 37 oz of oils.

My recipe in percentages looks like this:

Olive oil – 50%
Coconut oil – 32%
Shea butter – 8%
Avocado oil – 8%
Castor oil – 2%

To convert the above percentages you will multiply each ingredient’s percentage by 37 oz which is your total oils needed (or the 100%).

Olive oil – 37 x .5 = 18.5 oz
Coconut oil – 37 x .32 = 11.84 oz
Shea butter – 37 x .08 = 2.96 oz
Avocado oil – 37 x .08 = 2.96 oz
Castor oil – 37 x .02 = .75 oz

So your oils needed will be:

Olive oil – 18.5 oz
Coconut oil – 11.84 oz
Shea butter – 2.96 oz
Avocado oil – 2.96 oz
Castor oil – .75 oz

Run this through a lye calc to get the lye amount needed.

Lye – 5.28 oz (5% SF)

I double my lye amount to get my water amount. (Ignore the water amount the lye calc gives you.)

Water – 10.56 oz

So my final recipe is:

Olive oil – 18.5 oz
Coconut oil – 11.84 oz
Shea butter – 2.96 oz
Avocado oil – 2.96 oz
Castor oil – .75 oz
Lye – 5.28 oz

Water – 10.56 oz

This recipe will make a total of 52.85 oz of soap.

BB’s site states that the mold will hold 50 oz…so we’re good! I always prefer to have a bit extra than not enough.

If you want extra to make higher peaked soap…then calculate for extra soap.

Happy Soaping!

20 Responses

  1. Jonathan & Kaycie
    | Reply

    This is helpful. Thank you!

    The Sudsy Soapery, all natural, hand crafted soaps, bath fizzies, natural liquid soaps, homemade for you!

  2. Anne-Marie Faiola
    | Reply

    Lots of good info in this post! Great job on explaining it so well. :)

  3. Margaret
    | Reply

    Thank you…. you made it make sense to me….I love your blog…

  4. AMOF
    | Reply

    Muito interessante seu blog, descobri nas minhas pesquisa pela net para obter mais informações sobre o método cold process para fazer sabonetes, estou iniciando minha produção e fazendo muitos testes. Apesar de estarmos muito distantes, afinal estou no Brasil, a net pode fazer com que esta distancia seja percorrida em segundos e me possibilita ter acesso as informações valiosas que tem aqui em suas publicações.

    Obrigado pela atenção.

  5. Carrie
    | Reply

    Great, concise explanation that is easy to follow…..for the beginner and experienced soaper alike! Thanks for sharing this straight-forward system of conversion!

  6. Donna OShaughnessy
    | Reply

    Excellent post! I often will convert from one to the other but just by plugging in oil amounts until the right percentage shows up. Your way much less time consuming. THANKS

  7. Hope Cutbush
    | Reply

    Wonderful job explaining a how to convert a recipe to fit your mold. I love your blog and feel like I have a friend sitting in my kitchen helping me everytime I read your post. Thank you for sharing so freely the information that many of us need to make our soap turn out to be something that we are proud to give to others.

  8. Pooja
    | Reply

    Why do you multiply the lye by two to get the amount of water & ignore the lye calculator’s amount of water? Just courious?

    • Amanda
      | Reply

      Hi! I do it to simplify things. It’s easy to remember. The standard amount on lye calcs is usually more water than what I prefer and makes a softer soap that needs a longer cure. The standard lye water ration on soapcalc is 3:1 and that is just too high.

  9. Hilda Bahner
    | Reply

    Very useful . Thank you, thank you, thank you !

  10. Anne Hollin
    | Reply

    Thank you so much. This post was extremely helpful and easy to follow.

  11. I love shoes!
    | Reply

    Hi, this is VERY useful, thank you. Please can I ask, you say ‘I use the formula l (length) x w (width) x h (height) x .4 to determine how many ounces of oil my recipe needs to be.’ Please can you tell me what the .4 is? You state after it that you add 4oz for the fluffy top but I don’t understand what the initial .4 is in the formula. Thank you.

  12. John Stevenson
    | Reply

    This is really helpful when I first started making soap I struggled to get my head around that forumla, especially since in the UK we use gramms. Once I got a good set of digital scales that measures in oz it was so much easier to work out how much oil to use.

    So would that water ratio to lye just be 2:1? I just normally use the lye calculator recommendation, but would this need less time to cure?

  13. Amber
    | Reply

    Great info, simplified!!

    One question is in the BB lye calc what super fat % would you recommend??
    I tried the above amounts with diff % in the super fat column but didn’t get the amount of 5.28 as lye amount
    Could you please suggest the % or what would your recommendation be??

    Thanks!!! :)

    • Amanda
      | Reply

      I recommend a superfat of 5-8%.

  14. Jenna
    | Reply

    Thanks a ton… Makes total sense now.

  15. Colleen
    | Reply

    When I find SUPER helpful info on the internets, I like to pop on and say thank you. So, THANK YOU!! Pinning this for future reference and then others may find it useful as well. Cheers :-)

  16. Chase
    | Reply

    Why did you multiply the volume of the container by 0.4? Are taking 1 cubic inch of oil to be equivalent to 0.4oz ? Most vegetable oils average around 0.5 oz/cubic inch. Are you underestimating so you don’t overfill your container because you need to account for the water that will be added?

  17. Crystal
    | Reply

    Thank you so much for this. All of this makes perfect sense except the .4, I don’t understand why you multiply the volume of the container by .4?

  18. Katharina
    | Reply

    Does the extra .4 equate to 4% superfat?

Leave a Reply