1I know the finished fill weight
Best when you already know the combined wax + fragrance weight you want in one candle. This is the more direct method.
Candle Wax Calculator
Free candle-making tool
Plan the wax and fragrance to weigh for your batch
Start from a finished candle fill weight you already know, or make a planning estimate from the inside measurements of a straight-sided round jar. The calculator splits the target formula into wax and fragrance, then scales it to the number of candles you are pouring.
2Estimate a straight-sided round jar
Use inside diameter, usable fill height and your intended fill level. This route is a planning estimate, not a measured capacity.
Best data first: a known or tested finished fill weight gives the strongest starting point. If you do not have one, measured vessel capacity is stronger than estimating capacity from geometry alone.
For silicone molds, tapered vessels, square jars or irregular shapes, measure the real capacity instead. Use the Water-to-Wax Volume Converter, or the 3D Candle Mold Wax Calculator for supported regular mold geometry.
How the candle wax and fragrance calculations work
The direct method starts from a finished formula weight you already know. The round-jar method estimates that target from simple geometry before applying the same fragrance-load math.
Highest confidenceKnown or tested finished fill
Use the actual combined wax + fragrance fill weight for the same vessel and fill line when you have it.
Higher confidenceMeasured vessel capacity
Measuring the real cavity removes geometry error, although the volume-to-mass conversion still needs an appropriate factor.
Planning estimateRound-jar geometry
Useful before you have measured data, but wall shape, fill line and formula mass-per-volume can all move the result.
Split a known finished fill weight
Use this when you know the combined wax + fragrance weight you want in one finished candle.
Wax to weighTarget formula weight ÷ (1 + fragrance load)
Fragrance oilTarget formula weight − wax weight
Fragrance load in this calculator is a percentage of wax weight. That means an 8% load is 8 g of fragrance for every 100 g of wax—not 8% of the final scented mixture.
Worked example — 8 oz finished fill at 8%
Target formula8 oz
Fragrance load8%
Wax8 ÷ 1.08 = 7.41 oz
Fragrance8 − 7.41 = 0.59 oz
Weigh about 7.41 oz wax + 0.59 oz fragrance to target an 8 oz combined fill.
Supplier limit wins: a 6% starting load is common in candle making, but maximum fragrance capacity varies by exact wax. Use the specification for your material and confirm the finished candle with testing.
Estimate a straight-sided round jar
This route calculates a cylindrical fill volume, then converts that volume into a planning formula mass.
Fill volumeπ × radius² × usable fill height × fill %
Target formula massEstimated fill volume × planning mass factor
One cubic centimetre equals one millilitre, so centimetre dimensions give millilitres directly. The default 0.86 g/mL value is a general planning factor, not a measured density guarantee for every wax or scented blend. This is why the calculator labels the dimensions route as an estimate.
Worked example — 3 in diameter × 4 in usable height
Full cylinder volume≈ 463.3 mL
90% fill volume≈ 417.0 mL
At 0.86 g/mL factor≈ 358.6 g formula
At 6% fragrance load≈ 338.3 g wax + 20.3 g fragrance
The result is a planning target for this ideal cylinder, not a measured capacity of the real jar.
Use a measured method for higher confidence: tapered walls, thick decorative bases, square vessels and silicone molds do not match this cylinder model. Use the Water-to-Wax Volume Converter or the 3D Candle Mold Wax Calculator where appropriate.
Scale the batch and optional extra allowance
The calculator multiplies the per-candle formula by your candle count, then adds any extra formula you intentionally choose.
Base batchTarget formula per candle × number of candles
Prepared formulaBase batch × (1 + extra allowance %)
The extra allowance is not hidden waste added by the calculator. It defaults to 0% and only changes the batch when you select it. The final prepared formula is then split into wax and fragrance using the same fragrance-load percentage.
Unit integrity: grams and weight ounces represent the same mass, while inches and centimetres represent the same dimensions. The finished-fill input unit, jar-dimension unit and result unit are independent controls; switching any of them changes the display, not the underlying candle measurement.
Candle wax calculator FAQs
Answers about finished fill weight, jar capacity, fragrance load, the round-jar planning factor, units and batch allowance.
How much wax and fragrance do I need for an 8 oz finished candle?
If 8 oz is the combined finished fill target and fragrance load is 8% of wax weight, the calculator splits it to about 7.41 oz wax and 0.59 oz fragrance oil. The wax is 8 ÷ 1.08; fragrance is the remaining weight.
Does an 8 oz jar mean I should enter 8 oz as the finished fill weight?
Not necessarily. A jar may be marketed by fluid capacity or nominal product size. Fluid ounces measure volume, while the calculator's finished fill input is weight. Enter 8 oz only when 8 oz is the combined wax + fragrance weight you actually intend to put in the candle.
Is fragrance load based on wax weight or total candle weight?
In this calculator, fragrance load is a percentage of wax weight. For example, an 8% load means 8 g fragrance for every 100 g wax. Check the specification for your exact wax before choosing the percentage.
Why does the calculator start at 6% fragrance load?
About 6% is a common testing starting point used by many candle makers and suppliers, but it is not a universal recommendation or maximum. Some waxes allow less and some allow more. Your exact wax supplier's tested limit takes priority.
How accurate is the round jar method?
It is a planning estimate for a straight-sided cylindrical inside cavity. Real vessel shape, the actual fill line and the mass-per-volume of the finished scented formula can change the amount you need. A measured water-capacity method is stronger when precision matters.
What does the 0.86 g/mL planning mass factor mean?
It is a general planning conversion used only in the round-jar estimate to turn estimated fill volume into a target formula mass. It is not a claim that every candle wax or scented blend has a density of 0.86 g/mL. You can enter a custom measured factor or use the Water-to-Wax method instead.
Can I use the round jar method for silicone candle molds?
No. Sculptural and irregular molds rarely match a simple cylinder. Use the Water-to-Wax Volume Converter for a measured capacity, or the 3D Candle Mold Wax Calculator for supported regular mold shapes.
Should I measure wax and fragrance by weight or volume?
Use a scale to weigh the recipe. The dimensions method uses volume only as an intermediate planning step, then returns wax and fragrance as weights in grams or ounces.
What does the extra pour allowance do?
It optionally prepares 3%, 5% or 10% more finished formula for pitcher residue, small spills or topping off. It defaults to none. When enabled, the extra formula keeps the same selected fragrance load.
Will switching grams, ounces, inches or centimetres change my calculation?
No. The calculator preserves the same physical mass and dimensions internally when you switch units. A unit change should only change how the number is displayed, apart from normal display rounding.
Which method gives the most reliable candle wax result?
Use a known or tested finished fill weight when you have one. It avoids estimating the vessel capacity. If you do not know the fill weight, measuring the real capacity is generally stronger than relying on geometry. The round-jar method is best treated as a planning estimate before measured data is available.
Can I enter ounces but show the candle wax answer in grams?
Yes. The finished-fill input unit and the result unit are separate. You can enter a known fill in ounces and switch the answers to grams, or measure a round jar in inches and still display the wax and fragrance results in grams.
From batch quantity to a tested candle
Measure unusual molds more accurately, refine fragrance, choose a wick starting point, plan cooling and use real burn data before finalizing the candle.