candle math: how much wax and fragrance oil should i/you/we use?

stop wasting your candle-making materials!

you know how much your candle vessel can hold and you know the fragrance oil % you want to use - the max should be on the label - so enter those below to quickly get the amount of wax and fragrance oil to use.

note: use weight measurements like grams or ounces - not volume measurements like mililiters, cups or fluid ounces. the results below will be for the unit you used above.

how does this work?

content warning: math

the vessel weight will be the total of the amount of wax to use and the amount of fragrance oil to use. first you solve for the amount of wax to use:

amount of wax to use = vessel amount / (100% + fragrance oil %)

i wrote the work out on paper below, and you can also view the code here. on the right post-it is an example of 8 oz vessel with 10% fragrance oil:
$photo of two pink post-it note pads and in pencil i show the work for solving the equation a = b + cb - a is the amount of full vessel (wax + fragrance) which is known, b is the amount of wax to use which is unknown and what we're solving for, and c is the % of fragrance oil need which is known and depends on the wax and oil. a = b + cb is solved to a/(100% + c) = b. on the right note i give an example where a is 8 oz, c is 10% and that's solved to show that b (or the amount of wax to use) is 7.27 oz$

knowing the amount of wax to use, you can then subtract that from the vessel weight to get the amount of fragrance oil to use - in the example above, 8 - 7.27 = .73 ounces of fragrance oil. or you avoid doing math and just use that calculator i made up above!