How to calculate fragrance load
Two multiplications and one thing to watch for. Here is the method, worked at every load from six to ten per cent.
To calculate fragrance load as a percentage of wax, multiply the wax weight by the load and divide by one hundred: oil = wax × load ÷ 100. To calculate it as a percentage of the finished candle instead, multiply the total target weight by the load, then subtract the oil from that total to get the wax: wax = total − (total × load ÷ 100). Both are used, and they give different candles from the same percentage.
Fragrance load is a weight ratio, so calculating it is one multiplication. The part worth getting right is which weight you are taking a percentage of, because there are two conventions in common use and they do not produce the same candle.
Everything here is worked on a 500 g batch to keep it concrete, but the method is the same at any size. If you would rather not do it by hand, the fragrance oil calculator does both conventions at once and shows you what a batch would be called under the other one.
Worked at 500 g, load by load
The first two columns treat the load as a percentage of wax, adding oil on top. The third treats it as a percentage of the finished candle, taking the oil out of the total. The last column is what the first convention would be called under the second.
The three numbers you need
500 g × 8 ÷ 100. Added on top of the wax you already weighed.
Wax plus oil. Worth knowing if you are pouring to a target candle weight.
Which is why a scale reading in whole grams cannot hit a load accurately on a single jar.
The method, step by step
Not the jar, not the volume — the wax, in grams, on a scale accurate to 0.1 g. If you do not know how much wax your vessel takes, work it out with the wax calculator before you start.
Percentage of wax adds oil on top of the wax weight. Percentage of total takes the oil out of a fixed finished weight. Oil is a percentage of the wax, added on top of it. 500 g wax at 8% means 40 g oil and 540 g total.
Oil equals wax multiplied by the load, divided by one hundred. That is the whole calculation. Working in grams keeps it to one step; ounces introduce a conversion you do not need.
Compare the load to your wax’s rated maximum and to the fragrance oil’s own rating. Use the lower of the two. Neither is negotiable.
Calculate for the whole melt in one go. Calculating per candle and multiplying invites rounding errors that compound across a dozen jars.
Avoiding the common errors
Fragrance oils differ in density, so millilitres are not comparable between oils. Weight is the only ratio that holds.
Zero the scale with the empty jug on it, add wax to your target, zero again, then add oil to your calculated figure. No arithmetic in your head, no subtracting container weights.
On your batch card, next to the percentage. Six months later, "8%" on its own will not tell you which recipe you actually poured.
The load is a percentage, so it follows the wax weight. A bigger jar at the same percentage needs proportionally more oil, not the same amount.
Skip the arithmetic
Both conventions, your wax’s maximum, and the same batch expressed the other way.
Open the fragrance calculator →Print the numbers you keep looking up
One printable page — wax, fragrance load, wick sizing and pour temperatures. Free.
Estimates, not advice. Every figure on this page is computed from published reference values and standard measures, so your own inputs, equipment and conditions will move it. Nothing here is professional advice — talk to a qualified professional before acting on it.