How to Calculate Candle Wax and Fragrance
Candle making is both art and chemistry. The right amount of wax and fragrance determines scent throw, burn time, and safety. This guide covers the density math, fragrance load limits, and batch-scaling formulas that turn guesswork into precision.
The Wax Formula
Fragrance (oz) = Wax (oz) × (Fragrance Load% ÷ (100 – Fragrance Load%))
Wax is lighter than water: soy wax has a density of ~0.86 relative to water, so an 8 oz jar holds about 6.9 oz of wax. The fragrance is calculated as a percentage of the total candle weight (wax + fragrance combined), not just the wax weight.
Understanding Fragrance Load
Fragrance load is the percentage of the total candle weight that is fragrance oil:
- 6%: Light scent, good for subtle aromatics
- 8%: Medium scent throw — the sweet spot for most candles
- 10%: Strong scent throw — maximum for most soy waxes
- 12%: Very strong — only safe for certain paraffin blends
Watch Out: Exceeding your wax's maximum fragrance load causes "sweating" (oil leaching to the surface) and can be a fire hazard. Always check the manufacturer's maximum load for your specific wax. Soy 464 maxes at 10–12%. Some waxes cap at 6%.
Wax Density by Type
- Soy wax (Golden 464): 0.86 density — most popular for containers
- Paraffin (IGI 4630): 0.90 density — great scent throw
- Coconut/soy blends: 0.84 density — smooth tops, good adhesion
Pro Tip: To find your jar's volume in ounces, fill it with water to the desired pour line and weigh it. Water weighs ~1 oz per fluid ounce, so the weight in ounces equals the volume. This is more accurate than the jar's labeled size, which often refers to total capacity, not the usable fill line.
Scaling to Batches
For production runs, calculate the total wax and fragrance, then add 5–10% for losses during melting, pouring, and cleanup. A 12-candle batch of 8 oz jars needs about 82 oz of wax (5.1 lbs) and 7.1 oz of fragrance oil — plus a little extra to account for what sticks to the pitcher and thermometer.
Use the calculator above to get your exact amounts, whether you're making 1 candle or 100. Precision keeps your costs down and your candles consistent.