How much fragrance oil to use in candles — by wax type

Most advice on fragrance load stops at "use 6–10%." That number isn't wrong, but it's incomplete — it treats every wax and every fragrance oil as if they behave the same way, and they don't. Here's the version that actually accounts for the variables that change your real answer.

Start with your wax, not a flat percentage

Every wax has its own safe ceiling, because density and how the wax crystal structure binds oil molecules differ by type:

• Soy — up to 10%. The most forgiving wax to work with; scent binds well at moderate loads.
• Paraffin — up to 12%. Higher ceiling because paraffin's molecular structure holds more oil before separating.
• Beeswax — up to 6%. Beeswax already carries its own natural honey scent and binds added fragrance less readily than soft waxes — pushing past 6% is where seeping typically starts.
• Coconut — up to 10%. Similar ceiling to soy, but coconut wax is softer, so seeping shows up sooner if you're at the edge of the range with a heavy oil.
• Soy/paraffin blends — up to 10%, generally following the lower of the two component waxes.

Then check your specific fragrance oil, not just your wax

This is the step most guides skip. Your wax's max load is a ceiling — your fragrance oil's actual safe usage rate, set against IFRA (International Fragrance Association) guidelines, can sit well below it depending on the oil's ingredients. A "clean cotton" scent and a "vanilla bourbon" scent from the same supplier can have different real-world limits, because vanilla-heavy and musk-heavy blends tend to be denser and more prone to seeping at the same percentage a lighter floral would handle fine. Always check the supplier's data sheet for that specific oil — don't assume every scent in your cabinet shares the same ceiling.

The actual math

Fragrance oil (oz) = Wax weight (oz) × fragrance load (as a decimal)

Example: 16 oz of soy wax at 8% load → 16 × 0.08 = 1.28 oz of fragrance oil.

For a full batch, calculate per-candle wax weight first (container capacity × wax fill factor — see the wax comparison guide), then multiply by your chosen load percentage, then by your candle count.

Why "more fragrance" isn't the fix for weak scent

Once you're within the safe range, going higher rarely helps and often hurts. If a candle smells weak, the real cause is almost always one of these three things, not an under-loaded percentage:

1. The wick is too small. A small wick can't create a full melt pool, so it never releases enough vaporized fragrance while burning — this is a wick problem, not a fragrance problem.
2. It hasn't cured long enough. Soy and coconut candles need 1–2 weeks for fragrance oil to fully bind with the wax's crystal structure. Testing at 48 hours will make almost any recipe look underwhelming.
3. Fragrance was added above the oil's flash point. Adding fragrance oil into wax that's too hot burns off scent before it ever sets — you lose it before the candle is even poured, regardless of how much you added.

Quick reference

Use the low end of your wax's range while you're still testing a new fragrance oil, and only push toward the max once you've confirmed — through an actual cured test burn — that it doesn't seep or clog the wick at that level.