Recipes come in a lot of different forms. Most of the time, recipes are listed with specific units of measure. For example, a lip balm recipe might call for the following ingredients:
- 3 ounce Shea Butter
- 3 ounce Sweet Almond Oil
- 3 ounce Beeswax
- 3/4 ounce Flavor Oil
Other times, recipes are given in ratios, listing each component as a part or a percentage. In that case, the lip balm recipe might look like this:
- 1 part Shea Butter
- 1 part Sweet Almond Oil
- 1 part Beeswax
- .25 part Flavor Oil
Or, it could look like this:
- 31% Shea Butter
- 31% Sweet Almond Oil
- 31% Beeswax
- 7% Flavor Oil
The advantage of listing a recipe in parts or percentages is that it can be re-calculated to make any quantity you choose. The disadvantage is that you’ll need to do a little math in order to convert the equation into a usable recipe. Here’s how to do that.
Converting Parts to Percentages
- Convert the recipe into equally sized whole parts. Determine the smallest increment in your recipe, then divide the other parts by that increment. For example, our recipe calls for 0.25 parts of Flavor Oil, so I need to divide each whole part in the recipe by 0.25. After that, my recipe would look like this: 4 parts Shea Butter, 4 parts Sweet Almond Butter, 4 parts Beeswax, 1 part Flavor Oil.
- Convert the parts into fractions. Add the total number of parts in your recipe together. That number will be your denominator, the bottom number of each fraction. In our recipe, that number would be 13. The number of parts is each ingredient’s numerator. Assign each ingredient it’s numerator and denominator. After that, our recipe would look like this: 4/13 Shea Butter, 4/13 Sweet Almond Oil, 4/13 Beeswax, 1/13 Flavor Oil.
- Convert the fractions into percentages. Next, you’ll need to change those fractions into numbers that you can work with more easily. Here is a formula to help you do that. (
Divide the numerator of the fraction by the denominator (e.g. 4 ÷ 13=0.3076)
Multiply by 100 (Move the decimal point two places to the right) (e.g. 0.3076*100 = 30.76)
Round the answer to the desired precision.
Follow the answer with the % sign (e.g. 31%) After that, our recipe will look like: 31% Shea Butter, 31% Sweet Almond Oil, 31% Beeswax, 7% Flavor Oil.
Converting Percentages to Different Units of Measure
- Choose a unit of measure to work with. Metric units, such as grams or milliliters work best, as they are easier to do math with. You can always convert them back to English units at the end of the process. Visit our Conversions and Measurements Page for reference.
- Decide the desired size of your batch. For this example, let’s choose a ten ounce batch. That is equal to 283 grams.
- Determine the percentage of each portion of the recipe. Here is a formula that will help you do that: Multiply the number by the percent (e.g. 283 * 31 = 8773)
Divide the answer by 100 (Move decimal point two places to the left) (e.g. 8773/100 = 87.73)
Round to the desired precision (e.g. 87.73 rounded to the nearest whole number = 88) - Finalize the recipe. In our example, we’ve determined that 88 grams equals 31%, and 21 grams equals 7% of a ten ounce batch of lip balm. Now our recipe will look like this: 88 grams Shea Butter, 88 grams Sweet Almond Oil, 88 grams Beeswax, 20 grams Flavor Oil.
Converting Existing Recipes Using This Technique
You can also use these equations to change the quantities of recipes that are already set up for a particular quantity. To do this, you’ll first need to break down the recipe into equal parts, like you would with a recipe listed in parts. For example, we could take the lip balm recipe above, and convert it into grams. From there, we can break it down into a percentage and calculate a new quantity.
- 88 grams Shea Butter
- 88 grams Sweet Almond Oil
- 88 grams Beeswax
- 20 grams Flavor Oil
- Convert the recipe into fractions. Just like before, we will add up the parts, and use that number as the denominator of each fraction. The number of parts specific to each ingredient will the the numerator on each fraction. In this recipe, that would be: 88/284 Shea Butter, 88/284 Sweet Almond Oil, 88/284 Beeswax, 20/284 Flavor Oil.
- Convert the fractions into percentages. Next, you’ll need to change those fractions into numbers that you can work with more easily. Here is a formula to help you do that. (Divide the numerator of the fraction by the denominator (e.g. 88 ÷ 284=0.3098) Multiply by 100 (Move the decimal point two places to the right) (e.g. 0.3098*100 = 30.98) Round the answer to the desired precision. Follow the answer with the % sign (e.g. 31%) After that, our recipe will look like: 31% Shea Butter, 31% Sweet Almond Oil, 31% Beeswax, 7% Flavor Oil.
- Decide the desired size of your batch. For this example, let’s choose a 16 ounce batch. That is equal to 454 grams.
- Determine the percentage of each portion of the recipe. Here is a formula that will help you do that: Multiply the number by the percent (e.g. 454 * 31 = 14074) Divide the answer by 100 (Move decimal point two places to the left) (e.g. 14074/100 = 140.74) Round to the desired precision (e.g. 140.74 rounded to the nearest whole number = 141)
- Finalize the recipe. In our example, we’ve determined that 141 grams equals 31%, and 32 grams equals 7% of a sixteen ounce batch of lip balm. Now our recipe will look like this: 141 grams Shea Butter, 141 grams Sweet Almond Oil, 141 grams Beeswax, 32 grams Flavor Oil.
Keep in mind that when you change the quantity of a recipe by a large proportion that it may not behave exactly the same. Tiny increments can add up, so while a ratio works in a tiny batch, it might fail in a large one. Convert with caution!
Cindy says
Very nice article! Lots of very useful information. Thanks for taking the time to share. I am no good at math & really appreciate this post! 🙂
Elisabeth Wilks says
Thank you for this post. The whole formulation thing is hard for me and this was very helpful.
The Natural Beauty Workshop says
Hi Elisabeth,
Im so glad that we could help!
The Natural Beauty Workshop says
Hi Cindy. Were happy to be of help! Im so glad you found this post to be useful.
Anne-Marie Faiola says
This is so helpful, I find myself having to do conversions all the time and it’s easy to get mixed up. Thanks for this!
Audrey says
This is great! I find myself going to Google too often to try and look up conversion tips when I’m struggling. Nice to have all of this in one place.
roseanne says
This is very helpful. I often find it a bit difficult getting my head around the units of measure in recipes. Thank you for taking hte time to share this.
Kim Reimnitz says
Hello,
Thank you so much for posting this, it is extremely helpful. However, I am stuck on one part – the first part that says to take the smallest increment which is .25 – why is this? and are we assuming that a whole part is then 100? I am not such a mathematician and so I just need to get that basic part clear! I await in anticipation of the answer 🙂 Kindly, Kim
Kim says
So, with the above in mind, and the smallest part of a recipe would be for example 3 drops of essential oil, how would I then work out the parts to a recipe when that is such a small scale?
Example -* this is not a recipe but just for my understanding!
100 mls oil
15 mls vegetable butter
200 mls flower water
3 drops essential oil
the smallest part is the 3 drops of essential oil, so how would I put this recipe in parts to determine the bottom number for the fraction?
Mary Helen Leonard says
Hi Kim! Since a small amount of drops (3 for example) wouldn’t really be large enough to convert to another type of measure, I would be inclined to just leave that portion of the recipe as drops. You could, technically, try to convert the entire recipe to be measured by drops, but that would be tricky, and because different ingredients can add up to “drops” at different rates (due to texture, viscosity, etc.) you would also be at risk for throwing off the ratio all together.
The reason that we recommend dividing the recipe by it’s smallest portion (in the example’s case, 0.25) is to break the recipe down into an understandable ratio. Let’s look at it using money as an example instead.
Let’s say you had $4.50 but you wanted to count it in nickels instead of dollars. You would divide the whole sum by a nickel, or $0.05. Now you know you have 90 nickels.
Now let’s imagine that we have that same amount, but it has been counted up by it’s currency:
3 dollar bills
4 quarters
10 nickels
This time, we want to convert the whole recipe to dimes, which are not shown here. So we start by converting the whole thing to nickels.
3 dollar bills = 60 nickels
4 quarters = 20 nickels
10 nickels = 10 nickels
Now we have 90 nickels, and we can convert those nickels to dimes using a simple equation. X / 2 = Y.
3 dollar bills = 60 nickels = 30 dimes
4 quarters = 20 nickels = 10 dimes
10 nickels = 10 nickels = 5 dimes
I hope that explains the method a little bit more. I know it can be really tough to wrap your head around it all. It was tricky for me to really grasp it at first too. If you have a specific formula you’d like us to help you take a look at, please let us know. We’d be happy to help!
kim says
Dear Mary Helen,
Firstly I am so touched to receive such an in-depth and kind response, – thank you so much.
It will take a few times of my going over it, but I really love the creativity in your explanation and I know I will get it, – I will set myself some time later to read and re read!
Thank you for being so available here, it really is quite special,
with kind regards
Kim
patricia says
This was very helpful! Thank you so much.
Kelly Owens says
It’s our pleasure, Patricia. We’re so glad to hear you found the information helpful!