Guide
How much wax do I need for my candle jar?
Weigh the water your jar holds up to the fill line, then multiply by 0.86. The result is the total weight of wax and fragrance oil that fills the jar. A jar that holds 7.5 oz of water by weight takes about 6.45 oz of melted wax and oil.
The rest of this guide explains why that works, when to adjust the number, and how much wax common jar sizes need.
Why you can't fill an "8 oz" jar with 8 oz of wax
Jar sizes describe volume: how much liquid the jar holds, usually to the brim. Wax is bought and measured by weight. The two don't match for two reasons.
- Wax is lighter than water. Most container waxes weigh between 84% and 90% as much as the same volume of water. Suppliers call this specific gravity.
- You don't fill to the brim. Candles usually stop about ½ inch below the rim, so the wax sits well below the jar's rated capacity.
So an "8 oz" jar filled to a normal fill line usually takes about 6 oz of wax, not 8.
The water method, step by step
- Put the clean, empty jar on a kitchen scale and press tare so it reads zero.
- Fill it with water to where you want the finished wax surface to sit.
- Read the weight. This is the water weight, in ounces or grams.
- Multiply by 0.86, or your wax's specific gravity if your supplier lists it. This is your total pour weight.
- Dry the jar completely before you pour. Water left inside can cause adhesion problems and spitting wicks.
Total pour weight = water weight × 0.86
The water method works for any shape of vessel, including tapered tumblers and odd vintage containers, because you measure the space directly instead of trusting a label.
Splitting the pour into wax and fragrance oil
The total pour weight includes the fragrance oil. If you weigh out the full pour weight in wax and then add oil on top, the candle ends up slightly fuller than planned. To keep the same fill line, split the pour weight:
Wax = total pour ÷ (1 + fragrance load)
Fragrance oil = wax × fragrance load
Using the 7.5 oz example at an 8% fragrance load: 6.45 ÷ 1.08 = 5.97 oz of wax, and 5.97 × 0.08 = 0.48 oz of fragrance oil. Together they make the 6.45 oz pour.
Many makers simply weigh the full pour weight in wax and add oil on top. The difference is small, about a tablespoon in an 8 oz jar. Splitting is more accurate when fill lines need to match across a batch.
Wax and fragrance chart for common jar sizes
These figures assume the jar is filled to 90% of its brim capacity, a wax factor of 0.86, and an 8% fragrance load measured as a percentage of wax weight. Measure your own jars with water for exact numbers.
| Jar capacity | Water at 90% | Total pour | Wax | Fragrance oil (8%) |
|---|---|---|---|---|
| 4 fl oz (118 ml) | 3.76 oz | 3.23 oz / 92 g | 2.99 oz / 85 g | 0.24 oz / 7 g |
| 8 fl oz (237 ml) | 7.51 oz | 6.46 oz / 183 g | 5.98 oz / 170 g | 0.48 oz / 14 g |
| 9 fl oz (266 ml) | 8.45 oz | 7.27 oz / 206 g | 6.73 oz / 191 g | 0.54 oz / 15 g |
| 12 fl oz (355 ml) | 11.27 oz | 9.69 oz / 275 g | 8.97 oz / 254 g | 0.72 oz / 20 g |
| 16 fl oz (473 ml) | 15.02 oz | 12.92 oz / 366 g | 11.96 oz / 339 g | 0.96 oz / 27 g |
One fluid ounce of water weighs about 1.04 oz, which is why the water column is slightly higher than 90% of the capacity number.
When to change the 0.86 factor
0.86 is a widely used average. Published figures for container waxes range from about 0.84 to 0.90, and some suppliers list a specific gravity for each wax. Use your supplier's figure when you have it. If your candles keep coming out slightly over or under the fill line, adjust the factor by 0.01 or 0.02 and test again.
Wax also shrinks as it cools, and some waxes sink around the wick and need a second pour to top up. Keep a little extra melted wax aside for that.
How many candles does a pound of wax make?
Divide 16 oz by the wax per candle. With about 6 oz of wax in an 8 oz jar, 1 lb makes 2.7 candles, and a 10 lb bag makes about 26 before allowing for spills. The batch calculator does this for any jar and bag size.
Try it with your own jar. The wax & fragrance calculator takes your water weight or jar capacity and gives wax and oil amounts per candle and per batch, in ounces or grams.