Candle Wax & Fragrance Batch Calculator
Enter a water or unscented-wax fill measurement to plan the wax and fragrance oil for a batch. The calculation makes room for both ingredients, then adds your batch overage.
Wax to prepare (g)1,012.25
- Wax per candle (g)
- 160.67
- Fragrance oil per candle (g)
- 12.85
- Finished weight per candle (g)
- 173.53
- Fragrance oil to prepare (g)
- 80.98
- Approximate fragrance volume (mL)
- 85.24
- Total batch to prepare (g)
- 1,093.23
- Fragrance percent of finished candle
- 7.41%
Uses additive component volumes and water density of 0.9982 g/mL at 20°C.
Check the selected fragrance load against both the wax manufacturer’s capacity and the fragrance supplier’s applicable usage limit.
How to use this calculator
- Fill one empty vessel with water or unscented wax to the intended fill line, then record the net weight.
- Enter the vessel count and the density values for your actual wax and fragrance oil.
- Enter the supplier’s fragrance load and choose whether it is based on wax or finished blend weight.
- Choose an overage for pour-pot residue, spills, and any planned top-ups.
- Weigh the displayed wax and fragrance separately, then burn-test the finished combination.
How the batch quantity is calculated
A candle vessel holds a volume, while wax and fragrance are normally bought and weighed by mass. Start by measuring one vessel to the actual fill line, not to its rim. For a water measurement, the calculator estimates vessel volume as V = M ÷ 0.9982, where M is the water mass in grams and 0.9982 g/mL is the approximate density of water at 20°C. For an unscented-wax measurement, it uses V = M ÷ ρw.
The blend is then solved so the wax and fragrance volumes together occupy that vessel volume. With a wax-basis fragrance load p, the formula is W = V ÷ (1 ÷ ρw + p ÷ ρf) and F = p × W. W is wax mass, F is fragrance mass, and ρw and ρf are the wax and fragrance densities. This is why adding fragrance reduces the wax needed for a fixed fill line: the oil takes up some of the vessel volume.
If a supplier defines the load as a percentage of finished candle weight, the calculation instead uses T = V ÷ ((1 − p) ÷ ρw + p ÷ ρf), then W = (1 − p) × T and F = p × T. The result also shows the fragrance percentage of the finished candle. That makes a wax-basis recipe comparable with a limit stated for the final mixture.
What changes the result most
Vessel fill volume, wax density, and the selected fragrance convention have the largest effect. A water measurement is usually the simplest way to get the volume of an unfamiliar jar; a wax measurement can be useful once you have established the actual density of that wax. Fragrance oils are not all the density of water, so use the density or specific gravity in Section 9 of its safety data sheet when it is available.
Fragrance load is not a universal safety or performance setting. The wax maker’s fragrance capacity and the fragrance supplier’s applicable usage limit both matter; use the lower limit. A higher percentage can cause oil migration, poor burning, or compliance problems rather than a stronger scent.
What the calculation leaves out
The calculation treats wax and fragrance volumes as additive. Real blends can contract or expand slightly, and cooling shrinkage, trapped air, wet spots, and a second pour can change what fits in a vessel. It also cannot choose a wick or predict scent throw. Make test candles and burn-test every wax, fragrance, dye, vessel, and wick combination before production.
Worked example
For six vessels measured with 200 g of water, 0.86 g/mL wax, 0.95 g/mL fragrance oil, an 8% wax-basis load, and 5% overage, the vessel volume is about 200.36 mL. Solving the combined volume gives 160.67 g of wax and 12.85 g of fragrance per candle, for a 173.53 g finished candle.
For the batch, multiply each amount by six and then by 1.05. Prepare 1,012.25 g of wax and 80.98 g of fragrance oil, or about 85.24 mL of fragrance. The full batch is 1,093.23 g, and the 8% wax-basis recipe is 7.41% fragrance by finished weight.
Common questions
Is fragrance load based on wax weight or total candle weight?
It depends on the supplier’s convention. Most candle guidance states fragrance load as a percentage of wax weight, so 8% means 8 g of oil for each 100 g of wax. Some limits refer to the finished mixture, which is a different percentage; check the document that supplied the limit.
How do I measure a candle jar with water?
Tare the empty vessel on a scale, fill it with water to your planned candle fill line, and record the water mass. At ordinary room temperature, one gram of water is very close to one millilitre, so that mass gives the useful vessel volume. Dry the vessel fully before making candles.
Why does adding fragrance reduce the wax needed?
Both wax and fragrance oil occupy volume in the vessel. If the finished blend must reach the same fill line, the oil displaces a small amount of wax. Calculating wax from the vessel first and adding oil afterward can overfill the vessel.
How do I find wax and fragrance oil density?
Ask the wax supplier for a density value or determine it from a known wax weight and measured vessel volume. For fragrance oil, look in Section 9 of its safety data sheet for density or specific gravity. Density can vary with temperature and product formulation, so use values for the materials you are actually pouring.
How much extra wax should I prepare for a batch?
An overage of about 5% is a reasonable planning allowance for residue in the melting and pouring equipment, small spills, and top-ups. A first production test may need more because burn-test samples and failed pours also use material. Overage is material to prepare, not extra material to put into already full vessels.
Why are fluid ounces and net-weight ounces different?
Fluid ounces measure volume, while net-weight ounces measure mass. Wax and fragrance have different densities, so the same volume does not necessarily have the same weight. Weigh ingredients in grams for repeatable recipes, and convert fragrance volume only when a measuring device requires it.