How to use the candle wax calculator
- Enter your container capacity up to the fill line, in fluid ounces or millilitres.
- Enter how many candles you are making.
- Set the fragrance load and whether your supplier gives it as a % of wax or of total weight.
- Read the total wax to melt and the fragrance oil to weigh out.
Candle wax formula
Finished candle weight (oz) = Container volume (fl oz) × 0.86 Fragrance as % of wax: Wax = Fill ÷ (1 + FO%), Fragrance = Wax × FO% Fragrance as % of total: Fragrance = Fill × FO%, Wax = Fill − Fragrance
The calculator keeps the total equal to what your jar actually holds, so adding fragrance never overfills the container.
Worked example
Twelve 8 fl oz jars with 8% fragrance (by wax weight):
- Fill per jar = 8 × 0.86 = 6.88 oz
- Wax per jar = 6.88 ÷ 1.08 = 6.37 oz; fragrance = 0.51 oz
- Batch: 76.4 oz (4.78 lb) of wax and 6.1 oz of fragrance oil
Wax needed for common jar sizes
| Jar size | Finished weight | Wax (8% FO) | Fragrance (8%) |
|---|---|---|---|
| 4 fl oz (118 mL) | 3.44 oz (97.5 g) | 3.19 oz | 0.25 oz |
| 8 fl oz (237 mL) | 6.88 oz (195 g) | 6.37 oz | 0.51 oz |
| 10 fl oz (296 mL) | 8.60 oz (244 g) | 7.96 oz | 0.64 oz |
| 12 fl oz (355 mL) | 10.32 oz (293 g) | 9.56 oz | 0.76 oz |
| 16 fl oz (473 mL) | 13.76 oz (390 g) | 12.74 oz | 1.02 oz |
Pillar candles, molds and wax melts
The same method works for molds: fill the mold with water, measure the volume and enter it as the capacity. Pillar waxes are usually a little denser than container soy wax, so a factor of about 0.88–0.90 is often closer — make one test pillar and weigh it. For wax melt clamshells, enter the total volume of all cavities. Wax melts often use a higher fragrance load, up to the maximum your wax allows, because there is no wick to clog.
Candle making tips
- Weigh, don’t measure by volume. Fragrance oils and wax are always measured by weight on a kitchen scale.
- Add fragrance at the right temperature — usually around 185 °F (85 °C) for soy wax — and stir gently for 1–2 minutes so it binds.
- Make one test candle first. Weigh the finished candle to check the 0.86 factor for your wax and jar, then adjust the factor field.
- Melt about 10% extra for top-ups if your wax sinks around the wick as it cools.
- Let candles cure. Soy candles smell strongest after 1–2 weeks of curing before the first burn.