Enter your wax weight and fragrance load, and this calculator tells you how much fragrance oil to weigh out, in grams and ml. Add a pot count to get the amount per melt or candle. Results update as you type.
How fragrance load works
Fragrance load is the weight of fragrance oil as a percentage of the weight of your wax. At 8%, every 100 g of wax takes 8 g of oil, so 500 g of wax needs 40 g. Always weigh fragrance oil on digital scales rather than measuring by volume, as oils vary in density.
Each wax can only hold so much oil. Paraffin has a tighter, more uniform structure that binds fragrance well, so it tolerates loads up to around 12% and gives a strong hot throw. Soy is softer and more crystalline, so it usually tops out at about 10% and can take longer to cure before the scent peaks. Coconut blends sit close to soy, and palm holds less again.
More oil does not mean more scent. Past the wax's limit, oil the wax cannot hold seeps out as beads on the surface, known as sweating. You may also see a soft or greasy set, poor release from clamshells, frosting and a weaker throw. Overloaded wax is a safety risk too: loose oil can raise the risk of fire on a warmer and may take you over the safe limit on your fragrance's IFRA certificate, which also changes the CLP label you need. Your oil's maximum usage rate always takes priority over the wax's.
For more on oils and scent throw, read our fragrance oil load guide.
Typical loads by wax
| Wax | Typical load | Usual maximum | Notes |
|---|---|---|---|
| Soy | 6–10% | 10% | Cure for 1–2 weeks for best throw |
| Coconut blend | 6–10% | 10% | Creamy finish, good for clamshells |
| Paraffin | 8–12% | 12% | Strongest hot throw, fast cure |
| Palm | 5–8% | 8% | Prone to sweating when overloaded |
Check your supplier's figures: blends vary, so the maximum on your wax's spec sheet and on your fragrance oil's IFRA certificate both override this table. Use whichever is lower.
Frequently asked questions
- What fragrance load should I use for wax melts?
Most UK makers start at 8% and test from there. Soy and coconut blends usually sit between 6% and 10%, paraffin up to 12% and palm up to 8%. Never go above the maximum on your fragrance oil's IFRA certificate, even if your wax will hold more.
- Is fragrance load a percentage of the wax or the total batch?
This calculator uses the most common UK method: a percentage of the wax weight. 500 g of wax at 8% needs 40 g of fragrance oil, giving a 540 g batch. Some suppliers quote load as a percentage of the total batch instead, which works out slightly lower, so check which method your supplier means.
- Why are my wax melts sweating oil?
Beads of oil on the surface usually mean the load is higher than the wax can hold, or the oil was added at the wrong temperature and did not bind. Drop the load by 1 to 2%, add the oil at the temperature your wax supplier recommends and stir for a full two minutes.
- How do I convert grams of fragrance oil to ml?
Divide the grams by the oil's density. This calculator assumes 0.95 g/ml, which is typical, so 40 g is about 42 ml. Densities vary between oils, so weighing on digital scales is always more accurate than measuring by volume. Your oil's Safety Data Sheet lists its exact density.