Capacities
8 oz candle jar size guide
“8 oz” on a candle jar is a marketing size. It does not tell you whether it means fluid ounces of water, ounces of wax by weight, or how close to the rim the wax sits. Two jars sold as 8 oz can hold noticeably different amounts. Pick by measured capacity in millilitres.
Candle jar water capacity vs wax fill
We measure capacity with water. Water weighs about 1 g per ml. Soy and paraffin wax are lighter, roughly 0.8–0.9 g per ml, and you leave space under the rim. A practical rule of thumb: wax fill in grams is about 70–80% of the water capacity in millilitres, and 88% is the practical maximum, which leaves little headspace for the wick and burn. These are estimates based on water volume. Your wax blend, fragrance load, and fill line move the number, so always test pour.
Real jars around the 8 oz mark
| Model | Mouth / base / height (mm) | Water capacity (ml) | Approx. wax fill | Max fill (88%) |
|---|---|---|---|---|
| 7492 Candle Jar | 74/69/92 | 250 | 175–200 g | 220 g |
| 8090 Candle Jar | 81/76/91 | 315 | 221–252 g | 277 g |
| 80100 Candle Jar | 80/75/100 | 320 | 224–256 g | 282 g |
One US ounce by weight is about 28.35 g, so 8 oz of wax is about 227 g. On the 70–80% rule, a 250 ml jar like the 7492 lands at roughly 175–200 g, while the 8090 (315 ml) and 80100 (320 ml) bracket 227 g. That is why buyers who want “8 oz of wax” often end up on a 300 ml+ jar.
How to choose
- Decide the wax weight you want to put on the label.
- Divide by 0.7–0.8 to get the water capacity to look for.
- Shortlist moulds by capacity and mouth diameter (for wick and lid fit).
- Order samples and test pour your own wax.
All 101 moulds with millimetre sizes, water capacity, and wax fill estimates are in the Size Guide. Empty jars only. MOQ 240 pcs. Price on inquiry.