The short answer
Most guides suggest a total fragrance load somewhere between about 5% and 10% of the wax weight, with essential oils often started at the lower end of that range. The right number depends on your wax, the specific oil, and how strong a scent you want, so treat any range as a starting point and check your wax supplier’s guidance.
How to calculate fragrance load
Fragrance load is the percentage of scent oil, by weight, relative to the weight of the wax.
- Weigh your wax.
- Multiply that weight by the load you want, written as a decimal.
- Weigh out that amount of oil.
Example: 500 g of wax at a 6% load needs 500 x 0.06 = 30 g of essential oil.
Worked examples
| Wax weight | 5% load | 6% load | 8% load |
|---|---|---|---|
| 100 g | 5 g | 6 g | 8 g |
| 250 g | 12.5 g | 15 g | 20 g |
| 454 g (1 lb) | about 22.7 g | about 27.2 g | about 36.3 g |
How much for a 4 oz candle?
The key is whether “4 oz” means the weight of the wax or the volume of the container. Candle makers measure wax by weight. If you pour 4 oz (about 113 g) of wax by weight, a 6% load is about 0.24 oz or roughly 6.8 g of oil. A scale is far more reliable than converting to drops, because oils differ in density and drop sizes vary.
Ratios by wax type
These ranges come from supplier guidance and are general. Always check your own wax’s maximum.
- Soy wax (see types of soy wax): often cited at roughly 6% to 10%. Because essential oils are more volatile than fragrance oils, some guides suggest the upper half of the range, but start lower and test.
- Beeswax: often suggested lower, around 5% to 7%, because the wax has its own aroma.
- Coconut wax and coconut-soy blends: often cited higher, up to roughly 8% to 12%.
- Paraffin: commonly cited around 6% to 8%. For how paraffin and soy compare overall, see soy vs paraffin candle wax.
Why weigh instead of counting drops
Suppliers consistently recommend measuring essential oils by weight, not drops. Oils vary in density, and drops from different bottles are not the same size. Weight also makes it possible to repeat a good batch exactly.
What about the “30/50/20 rule”?
The 30/50/20 rule people mention is a blending guideline for the proportion of top, middle and base notes within a scent (one source describes 30% top, 50% middle, 20% base). It is not a ratio of oil to wax, so do not use it to decide your fragrance load. For blending, see mixing fragrances for candles.
Essential oils that should not be used in candles
Some essential oils are considered unsuitable or difficult in candles. Suppliers sometimes list specific oils as suitable only for wax melts, and some oils discolor wax or weaken when heated. Use oils sold for candle making where possible, read the supplier’s notes, and keep the load modest. Do not exceed the maximum your wax supports: guides warn that too much oil can leave the wax struggling to set, cause oil to separate or pool, or affect the flame.
Why your homemade candles may not smell strong
- The load may be low for that oil, or the oil may simply have a softer throw than fragrance oils.
- The oil may have been added at the wrong temperature. See when to add essential oil to soy wax.
- The candle may not have cured long enough. Suppliers commonly suggest around one to two weeks.
- The oil may be a top note that fades quickly under heat. Our list of the strongest essential oils for candles discusses which tend to hold up better.
Tips for testing
- Make small test candles with a different load each, and label them.
- Judge both cold throw and hot throw.
- Change one variable at a time, and record everything.
- Increase the load gradually, and stop if you see sweating, pooling oil, or a sputtering flame.
For a full workflow, see our DIY fragrance oil for candles guide.