Candle Making Calculator

Enter your container size and batch count to get the wax weight, fragrance oil weight and a starting wick size — in grams and ounces.

Where are you?

United States Europe & UK

AWG, NEC, 120/240 V, miles and gallons — we remember this on every calculator.

Container diameter

Measure across the inside of the jar at the widest point. This is what decides wick size, so measure rather than guess.

How do you know the container size?

I know its volume I will measure the fill height

Container volume

The size printed on the jar. Candle jars are sold by fluid ounces, which is a volume, not the weight of wax that fits.

How full will you pour?

Almost nobody fills to the brim. 90% leaves a sensible headspace and is what most jar-size rules of thumb assume.

How many candles?

Wax type

Density differs slightly between waxes, which changes how much weight fits in the same jar. Soy is the container default.

Fragrance load

The percentage of the total pour that is fragrance oil. 6% is subtle, 8% is standard, 10–12% is as much as most soy waxes will hold before it sweats out.

Wax needed

177 g

Wax in ounces: 6.22 oz
Fragrance oil: 15.3 g
Fragrance in ounces: 0.54 oz
Per candle (wax): 176 g
Per candle (fragrance): 15.3 g
Total pour weight: 192 g

🪿 The goose says: You need 177 g of soy (container blend) and 15.3 g of fragrance oil — buy about 10% extra to cover what sticks to the pot.

Wick starting point for a 2.80 in container: CD 12–14 / ECO 8–10 — one wick. Wick size is the one variable you cannot calculate — burn-test before you sell.
Buy about 10% more wax than this figure. Wax clings to the melting pot and pouring jug, and soy usually needs a small top-up pour after the first cool.

How this candle making calculator works

Candle jars are sold by volume and wax is sold by weight, and that mismatch is the whole problem. An 8 oz jar does not hold 8 ounces of wax — it holds 8 fluid ounces of space, which is about 6.8 ounces of soy once you account for density and headspace.

So the calculation runs: work out the space you are filling, decide how full to pour, convert volume to weight using the density of your wax, then split that weight between wax and fragrance oil.

The last step catches people out. Fragrance load is a percentage of the total pour, not something added on top. An 8% load in a 200 g pour means 184 g of wax and 16 g of oil, not 200 g of wax plus 16 g of oil.

Step 1 Volume of the container from the jar size, or π × (diameter/2)² × fill_height 1 US fluid ounce is 29.57 ml.
Step 2 How much of it you actually fill usable_ml = volume × fill% 90% is the normal pour, leaving headspace below the rim.
Step 3 Convert volume to weight pour_weight = usable_ml × wax_density Soy and paraffin are about 0.9 g/ml, beeswax 0.96.
Step 4 Split the pour between wax and oil fragrance = pour_weight × load% wax = pour_weight − fragrance
Step 5 Multiply by the batch total = per_candle × number_of_candles

Example: an 8 fl oz jar is 236.6 ml. Filled to 90% that is 213 ml, which in soy at 0.9 g/ml is a 192 g pour. At 8% fragrance that splits into 176 g of wax and 15 g of oil per candle.

Assumptions & caveats

Everything this calculator quietly assumes on your behalf. If one of these does not match your situation, the answer will be off.

Wax densities are 0.90 g/ml for soy and paraffin, 0.96 for beeswax and 0.92 for coconut-soy blends, measured solid at room temperature. Blends vary by a few percent between suppliers.
Fragrance oil is treated as part of the total pour weight, which is how fragrance load is defined in the industry. Some suppliers quote load as a percentage of wax weight instead — a 10% difference at the top end.
The default 90% fill level leaves normal headspace. If you pour to the brim, set it to 100 — but expect wax to overflow as it expands when hot.
Wick recommendations are starting points for a medium-melt-point container wax, based on container diameter. Wick size also depends on your wax, fragrance load and dye, and the only reliable test is burning a sample for four hours and checking the melt pool.
No allowance is made for wax left in the melting pot, the pouring jug or a top-up pour. Soy in particular usually needs a second small pour after the first cools and sinks. Buy about 10% over.
Container diameter is assumed constant. Tapered jars hold less than the widest measurement implies, so measure at the average width for those.
The calculator does not model dye, which is used in fractions of a percent and makes no meaningful difference to the wax weight.

Frequently asked questions

How much wax do I need for an 8 oz jar?

About 175–180 grams, or roughly 6.2 ounces, of soy wax for a standard 8 fl oz jar filled to 90% at an 8% fragrance load. The jar size refers to fluid ounces of volume, not the weight of wax, which is why the wax figure is lower than the number on the jar.

How much fragrance oil per pound of wax?

At an 8% load you use about 1.4 oz of fragrance oil per pound of finished candle, which works out to roughly 1.25 oz of oil per pound of wax. Most container soy waxes hold 6–10% comfortably; above that the oil tends to seep out as a film on the surface.

What wick size do I need?

Start from the container diameter: about CD 8–10 for a 2.5-inch jar, CD 12–14 for a 3-inch jar, and multiple wicks above 3.5 inches. This is a starting point only — the melt pool should reach the edge of the jar within about four hours without the flame mushrooming, and only a burn test tells you that.

Soy or paraffin wax — which is better?

Paraffin throws scent more strongly and gives a smooth, glossy finish; soy is renewable, burns longer and cooler, and is what most small makers use. Soy is also more temperamental: it frosts, it sinks, and it usually needs a top-up pour. If you want the easiest good result, start with a container soy blend like GW 464.

Why do my candles tunnel?

Almost always an undersized wick, occasionally a first burn that was cut short. The first burn sets the memory ring, so it needs to run until the melt pool reaches the jar wall — usually three to four hours. If a correctly-sized wick still tunnels, the fragrance load or dye is choking the flame.

How long should candles cure before burning?

One to two weeks for soy, three to five days for paraffin. Curing lets the fragrance oil bind fully into the wax, and a soy candle burned the day after pouring will smell noticeably weaker than the same candle two weeks later. It costs nothing but patience.

How do I stop soy wax frosting?

Pour cooler, around 120–135 °F, warm the jars first, and cool the finished candles slowly at room temperature rather than in a draught. Frosting is soy recrystallising and is cosmetic only — it does not affect burn or scent, and no soy wax avoids it entirely.