It is the first question every maker asks, usually standing over a pot of melted soy wax: how much oil do I put in? The honest answer is a range, a caveat and one piece of arithmetic that most guides skip. Here are all three.
The fragrance oil percentage chart
These are working loads — where most makers land after testing — not limits. The limit for any particular oil is on its IFRA conformity certificate, and it can be lower.
| What you are making | Typical load | What really limits it |
|---|---|---|
| Paraffin candle | 6–12% | The wax maker’s stated maximum and your wick |
| Soy / container soy candle | 6–12% (many soys specify 8–10%) | Cure time — judge at day 10–14 |
| Coconut-blend candle | 6–12% | The blend; retention varies lot to lot |
| Beeswax candle | 3–6% | Beeswax simply holds less |
| Reed diffuser | 15–30% in the base | Above ~30% the reeds clog and it slows down |
| Room spray | 3–8% | How much the carrier will dissolve |
| Cold-process soap | 3–6% on oil weight | Acceleration, and top notes lost to lye |
| Melt-and-pour soap | 1.5–3% | The base is already soap |
| Shampoo | 0.3–1.0% | The surfactant system |
| Liquid detergent | 0.3–0.8% | Only what lands on cloth counts |
| Eau de parfum | 10–20% | Nothing regulated — EDP is a marketing term |
“10%” of what, exactly?
This is where people lose money without noticing. Ten percent of the wax is not ten percent of the candle. Put 20 g of oil into 200 g of wax and your candle weighs 220 g, of which the oil is 9.09%. Put 10% into the finished candle instead and you need 20 g of oil in a 200 g candle — 180 g of wax.
Neither is wrong. But when two suppliers quote “10%”, one may mean wax weight and the other finished weight, and on a production run that is a tenth of your fragrance bill. Soap has the same trap in a different place: soapmakers quote on oil weight, while the IFRA certificate talks about the finished bar. Convert before you compare.
Calculator
Common questions, answered with numbers
How much fragrance oil for an 8 oz candle?
8 oz by weight is about 227 g of wax (many “8 oz” jars actually hold a little less — weigh yours). At 8% of the finished candle that is roughly 18 g of oil; at 10% of the wax it is about 23 g. Weigh it — don’t measure by volume. Fragrance oils vary in density, so millilitres and grams are close but not the same.
How much fragrance oil per 100 g of soy wax?
At a typical 8–10% of wax weight, 8–10 g. Then stop and let it cure for a week or two before deciding it is weak. Most over-dosed soy candles were judged on day one.
How much fragrance oil per pound of soap?
A pound of soaping oils is about 454 g. At 3–6% of oil weight that is roughly 14–27 g. Start low with anything spicy or floral-sweet: cinnamon, clove and some floral aldehydes can seize cold-process batter.
Before you push the percentage up
When a candle throws weakly, the fix is rarely more oil. Check the wick first — throw follows the size and temperature of the melt pool, and one wick size up costs paise. With soap, a “weak” citrus is usually a citrus that didn’t survive the lye, and more of it won’t help; anchor it with a wood or a musk instead.
And compare oils per finished unit, not per kilo. A ₹1,900/kg oil that works at 5% in a 200 g candle costs ₹19 of fragrance; a ₹900/kg oil that needs 10% costs ₹18 — and ships twice the weight.
Where the limit actually lives
Everything above is a starting point. The ceiling for a specific oil in a specific product is on its IFRA conformity certificate, which lists a maximum for each product category. Candles and air fresheners sit in category 12, for products with no skin contact; soap and shampoo sit together in a rinse-off category with lower limits. Ask for the certificate with the sample, not after the first order.
If you want to test before you commit, every oil in our candle, soap and diffuser ranges comes as a 30 g sample.
Quick answers
- How much fragrance oil do I add to a candle?
- Typically 6–12% for paraffin, soy and coconut blends, and 3–6% for beeswax, always below the wax maker’s stated maximum and the IFRA certificate for that oil.
- How much fragrance oil do I add to soap?
- Around 3–6% of oil weight for cold-process soap and 1.5–3% for melt-and-pour, checked against the IFRA certificate for the rinse-off category.
- Is fragrance load measured by weight or volume?
- By weight. Fragrance oils vary in density, so weigh them rather than measuring in millilitres.
Related: Candle fragrance · Soap fragrance · Reed diffuser oil