Candle wax calculator
A fill of 236.6 mL weighs 212.93 g: 197.16 g of wax and 15.77 g of fragrance oil for each candle.
Result
Wax per candle
g
Fragrance oil per candle
g
| Wax volume (jar volume times how full) | 236.59 mL |
|---|---|
| Specific gravity of the wax | 0.90 g/mL |
| Fill weight (volume times gravity) | 212.93 g |
| Wax per candle | 197.16 g |
| Fragrance oil per candle | 15.77 g |
| Wax for the batch | 197.16 g |
| Oil for the batch | 15.77 g |
| Wax and oil for the batch | 212.93 g |
How it works
A jar is sold by volume but wax is weighed. The tool multiplies the volume you fill by the wax's specific gravity, its weight compared with the same volume of water, to get the weight of the finished fill. It then splits that weight into wax and fragrance oil at the percentage you choose. For a batch it multiplies by the number of candles and adds an allowance for wax that stays in the pot. Use it to find how much wax you need for a batch of candles before you melt anything.
Formula
Jar volume V: jar_basis volume -> V = jar_volume; jar_basis water -> V = water_mass / water_density (1000 kg/m3). Filled volume Vf = V x fill_pct. Specific gravity: soy 900, paraffin 900, beeswax 970 kg/m3 (constants.wax_gravity_kg_m3), or the user's gravity for wax = custom. Fill weight M = Vf x gravity (the oil is assumed to weigh what the same volume of wax weighs). Load p = fragrance_load. load_basis wax (fragrance load, oil relative to wax): W = M / (1 + p), O = W x p. load_basis total (fragrance content, oil relative to wax plus oil): O = M x p, W = M - O. Batch with n candles and pot allowance e: wax_batch = n x W x (1 + e), oil_batch = n x O x (1 + e), batch_total = n x M x (1 + e). load = O / W, content = O / M.
Worked example
The calculator opens with this example; the result above is computed from it.
| Input | Value |
|---|---|
| How you know the jar size | Volume (fluid ounces or milliliters) |
| Jar volume | 8 US fl oz |
| How full | 100 % |
| Wax | Soy wax |
| The percentage is of | The wax (fragrance load) |
| Fragrance percentage | 8 % |
| Number of candles | 1 pcs |
| Extra for the pot | 0 % |
| Wax per candle | 197.16 g |
| Fragrance oil per candle | 15.77 g |
Common cases
| Case | Starting values | Wax per candle | Fragrance oil per candle |
|---|---|---|---|
| Single eight-ounce jar | Jar volume 8 US fl oz; How full 100 %; Fragrance percentage 8 %; Number of candles 1 pcs; Extra for the pot 0 % | 197.16 g | 15.77 g |
| Travel tin | Jar volume 4 US fl oz; How full 100 %; Fragrance percentage 8 %; Number of candles 1 pcs; Extra for the pot 0 % | 98.58 g | 7.89 g |
| Batch of twelve jars | Jar volume 9 US fl oz; How full 95 %; Fragrance percentage 8 %; Number of candles 12 pcs; Extra for the pot 5 % | 210.71 g | 16.86 g |
| Jar measured with water, paraffin | Water the jar holds 250 g; How full 100 %; Fragrance percentage 6 %; Number of candles 6 pcs; Extra for the pot 5 % | 212.26 g | 12.74 g |
Assumptions and limits
- The wax figures are typical values from the sources named on this page. Brands differ, so use your supplier's number for an exact fill.
- The oil is assumed to take the same volume as the wax it replaces, so the fill weight does not change with the load.
- The wick, its tab and any decoration are not subtracted from the volume.
- Water is taken as one gram per milliliter.
- Fluid ounces are US fluid ounces. A fluid ounce measures volume and an ounce measures weight; they are not the same thing.
- The pot allowance is added to both wax and oil in the batch figures.
The result is an estimate for planning, not professional advice.
Sources
- Candlemaking (AU) safety data sheet, soy wax flake GW464: specific gravity 0.9, about 7.6 lb per gallonretrieved 2026-10-12
- Candle Shack: fragrance load is oil over wax; fragrance content is oil over wax plus oil, with worked gramsretrieved 2026-10-12
- Craftybase candle fragrance load calculator: container size x wax gravity = fill weight, worked example 8 oz, 0.86, 6 %retrieved 2026-10-12
- NIST SP 811 Appendix B: US fluid ounce, ounce, pound (exact conversion factors)retrieved 2026-10-12
Last updated:
Method in depth: Wax weight from volume: specific gravity and the ounce problem
Cite this page: Candle Math, “Candle wax calculator”, https://candle-math.pages.dev/candle-wax/candle-wax-calculator/ (updated 12 October 2026).
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