Guide
How much fragrance oil should you add to candles?
Multiply the weight of your wax by your fragrance load. At an 8% load, 1 lb (16 oz) of wax takes 1.28 oz of fragrance oil, and 1 kg takes 80 g. Many makers start soy container candles between 6% and 10% and stay under the maximum listed for their wax.
What fragrance load means
Fragrance load is the amount of fragrance oil in a candle, written as a percentage. It is always worked out by weight, never by volume, because oils vary in density.
There are two ways to state it, and suppliers don't all use the same one.
- Percent of wax weight. Common in the US. 8% means 8 g of oil for every 100 g of wax.
- Percent of total weight. Common in Europe. 8% means 8 g of oil in every 100 g of finished candle, so 92 g of wax.
Percent of wax: oil = wax × load
Percent of total: oil = wax × load ÷ (1 − load)
The gap grows with the load. 10% of wax weight equals 9.1% of total weight. 10% of total weight equals 11.1% of wax weight. When a wax is rated for "up to 10%", check which basis the supplier means before you push close to the limit.
Fragrance oil per pound or kilogram of wax
| Fragrance load (of wax) | Per 1 lb of wax | Per 1 kg of wax |
|---|---|---|
| 6% | 0.96 oz | 60 g |
| 8% | 1.28 oz | 80 g |
| 10% | 1.60 oz | 100 g |
| 12% | 1.92 oz | 120 g |
Typical maximum fragrance load by wax
Every wax has a limit to how much oil it can hold. These are typical published ranges. Your wax's technical data sheet is the figure to follow.
| Wax | Typical maximum | Notes |
|---|---|---|
| Soy (container) | 10–12% | The most common container wax. Many makers start around 6–10%. |
| Coconut and coconut-soy blends | 10–12% | Soft, creamy waxes made for containers. |
| Paraffin and paraffin blends | About 6–10% | Varies widely by blend. Some are rated higher. |
| Beeswax | About 6% or less | Has its own honey scent and holds less added oil. |
Why more oil doesn't always mean a stronger candle
Past the wax's limit, the extra oil has nowhere to go. It can pool on the surface or seep out of the candle, a problem makers call sweating. Overloaded candles can also burn poorly and leave soot on the jar. A candle at a sensible load with the right wick usually smells stronger than an overloaded one.
How strong a candle smells depends on several other things too:
- The wick. A wick that's too small never builds a full melt pool, so less scent is released.
- Cure time. Soy candles are often left to cure for one to two weeks before burning.
- When you add the oil. Add it at the temperature your wax supplier recommends and stir gently for a couple of minutes so it binds with the wax.
- The fragrance itself. Some oils are simply stronger than others at the same load.
A worked example
You're making 12 soy candles with 6 oz of wax each at an 8% load.
- Total wax: 12 × 6 oz = 72 oz (4.5 lb).
- Fragrance oil: 72 × 0.08 = 5.76 oz.
- Per candle: 6 oz wax plus 0.48 oz oil.
If your supplier states 8% of total weight instead, the oil is 72 × 0.08 ÷ 0.92 = 6.26 oz.
Check the safety documents too
Fragrance suppliers provide an IFRA certificate and a safety data sheet for each oil. The IFRA certificate lists the maximum level that oil can be used at in candles, which can be lower than your wax's limit. Keep these documents on file, especially if you sell your candles.
Skip the arithmetic. The wax & fragrance calculator handles both percentage styles and flags a load above your wax's typical maximum.