What Is Fragrance Load in Candle Making?

Fragrance load is how much fragrance oil you put in a candle, written as a percent of the wax weight. If you pour 16 oz (454 g) of wax and add 1.28 oz (36 g) of oil, your load is 8 percent. Always weigh both on a scale, because oils vary in density and a measuring cup will be off.

How do I work out fragrance load?

Divide the weight of the oil by the weight of the wax, then multiply by 100. Going the other way, multiply the wax weight by the load.

Example (all numbers are made up for the math):

• Wax: 16 oz (454 g)
• Load: 8 percent, which is 0.08 as a decimal
• Oil: 16 x 0.08 = 1.28 oz. In grams, 454 x 0.08 = 36.3 g

Many US suppliers talk in ounces of oil per pound of wax. One ounce per pound is 1 / 16 = 6.25 percent. To convert, multiply the percent by 16 and divide by 100: 8 percent is 8 x 16 / 100 = 1.28 oz per pound. That matches the example above, which is a good sign the math holds.

What if I know the total batch weight and not the wax weight?

This is where makers get tripped up. If the load is a percent of the wax, the wax is not the whole batch. The batch is wax plus oil, so:

wax = batch weight / (1 + load as a decimal)

Say you want a 500 g batch at 8 percent:

• Wax: 500 / 1.08 = 463 g
• Oil: 463 x 0.08 = 37 g
• Check: 463 + 37 = 500 g

The shortcut of 500 x 0.08 = 40 g of oil leaves 460 g of wax, and 40 / 460 is 8.7 percent. That is close, but not what you meant, and the gap grows when you scale to big batches. Some suppliers do express load against the total weight instead, so check which one your supplier's sheet uses before you copy a number. We cover that split in the guide on whether load is a percent of the wax or the total.

What is a normal fragrance load?

It depends on the wax and the oil. One supplier guide lists soy at 6 to 10 percent, with 8 percent as a common starting point, and beeswax much lower at 3 to 6 percent. Another supplier tells makers to go up a wick size or two when they use more than 1 oz per pound (6.25 percent) and down a size or two when they use less. Treat these as starting points, not rules. The maximum your wax can hold is on your wax maker's tech sheet, and it changes by brand.

Why not just add more oil?

Because every wax has a ceiling. Past it, the oil has nowhere to go. Supplier guides list the same trouble signs:

• Oil seeping out of the wax, often called sweating or bleeding
• The wax pulling away from the jar
• Soot, because more fuel is being drawn up the wick
• A wick that drowns in the melt pool
• Pooled oil on top, which is a fire hazard if it ignites

A stronger smell in the bottle does not mean a stronger candle. Some oils also have a low flash point, which changes the temperature you add them at. It does not mean you should use less. Read the oil's safety data sheet for that.

Does load decide how strong the candle smells?

It helps, but it is not the only thing. Cold throw (the smell of the unlit candle) and hot throw (the smell while burning) can differ a lot between oils at the same load. Cure time, wick size and the jar all move the result too. The only way to know is to pour a test candle, let it cure, and burn it.

Common mistakes

• Measuring oil by volume. Weigh it.
• Mixing up percent of wax and percent of total. Pick one and write it on the recipe.
• Pushing past the wax maker's maximum to chase scent.
• Changing the load and keeping the same wick. More oil changes how the candle burns, so retest.
• Copying a number from a forum without checking your wax brand.

Questions

Is 10 percent fragrance load too much?

It can be fine in some waxes and too much in others. Some supplier guides list 10 percent as a sweet spot for coconut or paraffin and as the top of the range for soy. Your own wax maker's maximum is the number that counts, and a burn test in your jar is what proves it.

How much fragrance oil do I need for a 9 oz candle?

If 9 oz is the wax weight and you want 8 percent, that is 9 x 0.08 = 0.72 oz (20 g). If 9 oz is the finished candle including oil, divide 9 by 1.08 first to get 8.33 oz of wax, then take 8 percent of that, which is 0.67 oz (19 g).