Fragrance oil to wax ratio explained
How much oil each wax will actually hold, why the same percentage can mean two different amounts, and what happens when you go over.
Most container waxes take a fragrance load of 5% to 12% by weight, with soy usually settling around eight per cent. The ratio is always calculated by weight, never by volume, and is normally quoted as a percentage of the wax rather than of the finished candle.
Fragrance load is the ratio of fragrance oil to wax, by weight. It is the number that decides whether a candle smells like anything, and it is capped — not by taste, but by how much oil the wax can physically hold before it starts separating out.
Two things make it more confusing than it should be. The first is that each wax has its own ceiling, set by the manufacturer, running from about 6% for beeswax up to 12% for paraffin and coconut blends. The second is that "8%" means two different amounts of oil depending on whether the person writing the recipe meant eight per cent of the wax or eight per cent of the finished candle.
The table below gives the working figures for every common wax. The fragrance oil calculator handles both conventions and shows you the same batch expressed either way, which is the quickest way to translate someone else’s recipe.
Fragrance load by wax
Typical and rated maximum loads as a percentage of wax weight, with what the typical load works out to for a one-pound batch. Your own wax and oil each publish a maximum — use the lower of the two.
What a percentage point is worth
Oil added on top of the wax. The finished candle weighs 540 g.
The same weight of oil, but it is part of the finished candle, so you only pour 460 g of wax.
On a 500 g batch. Small enough that a scale reading in whole grams is not precise enough to hit a target load reliably.
What decides the ratio
This is a physical limit, not a guideline. Past it the wax cannot hold the oil in suspension and it separates — you get oily patches, pooling around the wick and a candle that sweats in a warm room.
Fragrance oils are also rated, usually for skin safety and flashpoint rather than for wax capacity. Where the two maximums disagree, the lower one is your ceiling.
The same number produces different candles. Of wax, the oil is added on top; of total, the wax is reduced to make room. Recipes rarely say which they mean, and most suppliers mean percentage of wax.
Oil added to wax that is too hot flashes off before it ever binds, so the candle smells weak despite a correct load. Too cool and it does not disperse evenly. Follow the wax manufacturer’s stated adding temperature.
Throw depends on melt pool size. An under-wicked candle at the maximum load will smell weaker than a correctly wicked one well below it — see the wick size chart.
Working with fragrance load
Fragrance oils vary in density, so millilitres are not interchangeable with grams between oils. Every figure on this page is by weight.
On a typical single-jar batch, one percentage point is only a few grams. A scale reading in whole grams cannot hit a target load consistently.
If a candle smells weak, do not raise the load and change the wick in the same test. You will not know which one fixed it.
Fragrance keeps binding into the wax for days after the pour. Judging throw on a candle poured yesterday tells you very little — give soy a week or two.
Work out your own load
Enter your wax weight and load, either convention, and get the oil weight with your wax’s maximum shown.
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.