The percentage is of what, exactly
Take an eight fluid ounce jar and a wax that fills it at 0.86 ounces per fluid ounce. The jar holds 6.88 ounces of finished candle. Now apply an eight percent fragrance load, and there are three defensible answers:
| Basis | Wax | Fragrance | Finished | Fits an 8 fl oz jar |
|---|---|---|---|---|
| Of the finished candle | 6.330 oz | 0.550 oz | 6.880 oz | Yes, exactly |
| Of the wax, scaled to fit | 6.370 oz | 0.510 oz | 6.880 oz | Yes, exactly |
| Of the wax, added on top | 6.880 oz | 0.550 oz | 7.430 oz | No — about 8.6 fl oz |
The third row is the common one, because the obvious procedure is to work out the wax from the jar volume and then add fragrance to it. It produces a candle eight percent taller than the jar was measured for, which either raises the pour line or leaves wax in the pitcher across the batch. Over twelve jars that is most of a jar worth of mix with nowhere to go.
None of the three is wrong as a recipe. What is wrong is comparing a load quoted on one basis with a load calculated on another, which happens constantly because almost nobody says which they mean.
Fill weight per fluid ounce is not a constant
The figure of 0.86 gets passed around as if it were a property of candles. It is a rough density ratio for one family of wax, and it moves with the wax, with how much fragrance and dye are in it, and with how completely the wax has set. If your jars come out consistently over or under the pour line, this is the number that is wrong.
Measuring it takes one candle. Pour a known volume, let it set for a day, weigh what you poured. Divide weight in ounces by volume in fluid ounces and you have your own figure, specific to your wax and your process, which is worth more than any published number.
Where the wax goes that does not reach a jar
The pitcher loss allowance covers wax and fragrance clinging to the pouring vessel, the thermometer and the stirrer. On a single candle it is trivial. On a batch of forty it decides whether the last jar fills, and the last jar is always the one that comes up short, because that is the one being poured when the pitcher runs out.
The allowance applies to fragrance as well as wax, which people forget. Anything left in the pitcher is mixed, so it carries its share of the fragrance out with it.
Two things this page will not do
It will not size a wick. Wick choice is a burn test: you make candles with several wick sizes in the actual wax, the actual fragrance and the actual container, and you watch them burn for hours. There is no formula, and any page offering one is guessing on your behalf. What is here is the length to cut, which is geometry and nothing else.
It will not tell you a maximum fragrance load. The wax manufacturer states how much the wax will hold, and the fragrance supplier documentation states use levels for that fragrance. Those are the authorities, they differ between products, and anything sold to the public sits under labelling rules that vary by jurisdiction.
If your wax comes from your own hives, the beeswax yield calculator works the other direction, from comb to rendered wax to how many candles that weight makes. For costing a batch across several bought-in materials at once, the craft cost per unit calculator handles the packs and the leftovers.
Molten wax burns on contact and it sticks to skin while it cools. A wax fire behaves like a fat fire and water makes it worse, violently.
Questions people ask
How much wax does an 8 oz jar need?
Less than eight ounces, because the jar is measured in fluid ounces and wax is weighed in ounces of weight. At a fill weight around 0.86 ounces per fluid ounce, an eight fluid ounce jar holds roughly 6.9 ounces of finished candle, and the wax is that figure minus whatever the fragrance takes. The eight on the jar is a volume, not a weight, and treating it as a weight overfills by about sixteen percent before fragrance is even considered.
Should the fragrance percentage be of the wax or the total?
That is a recipe convention and both are used, which is precisely the problem. What matters is that you know which one you are using and which one any figure you are comparing against uses. This page will do it either way and shows what the same load looks like expressed the other way round, so you can check a supplier figure against your own without having to redo the arithmetic in your head.
What fragrance load should I use?
This calculator does not have an opinion and should not have one. The wax manufacturer states the maximum the wax will hold before it stops binding, and the fragrance supplier documentation states use levels for that specific fragrance. Those two figures come from the products in front of you, they differ between products, and going above them does not produce a stronger candle so much as a candle that weeps. Enter the number your documentation gives.
How long should I cut the wicks?
The inside height of the container plus enough above the rim to sit in a centring bar and be held while the wax sets, which is what this page calculates. Around an inch and a half above the rim is comfortable for most setups. That is the cutting length, not the burning length: the wick gets trimmed right down before the candle is lit, and how far down is a burn test question along with the wick size itself.
Why does the batch need more wax than the candles do?
Because some of it never reaches a jar. Wax and fragrance cling to the pouring pitcher, the thermometer and anything else that goes into the melt, and that film is gone whether you pour ten candles or a hundred. The allowance matters most at the end of a batch, since a pitcher that comes up short leaves the last jar under-filled, and topping up a partly set candle leaves a visible line.