How to Calculate Fragrance Load for Any Wax (With Formula)
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How to Calculate Fragrance Load for Any Wax (With Formula)
Fragrance load is one of the most important — and most misunderstood — variables in candle making. Too little and your candle barely smells. Too much and the fragrance oil can't bind to the wax, causing safety issues and poor burns. This guide gives you the exact formula, quick-reference tables for every major wax type, and worked examples so you never have to guess again.
What Is Fragrance Load?
Fragrance load (sometimes called fragrance percentage or FO ratio) is the amount of fragrance oil expressed as a percentage of your total wax weight.
It tells you: for every 100 grams of wax, how many grams of fragrance oil do you add?
An 8% fragrance load on a 100g batch = 8g of fragrance oil.
An 8% fragrance load on a 500g batch = 40g of fragrance oil.
Simple in theory — but getting it right for your specific wax, fragrance oil, and container makes all the difference.
The Formula
The Fragrance Load Formula
Fragrance Oil (g) = Wax Weight (g) × Fragrance Load (%)
Example: 500g soy wax × 8% = 40g fragrance oil
That's it. The math is simple — the art is knowing which percentage to use for your wax type. Here's your reference:
| Wax Type | Minimum | Maximum | Sweet Spot | Notes |
|---|---|---|---|---|
| Soy Wax | 6% | 10% | 8% | Most popular starting point for containers |
| Paraffin Wax | 6% | 12% | 10% | Higher loads work well due to paraffin's structure |
| Coconut Wax | 8% | 12% | 10% | Excellent fragrance binder; holds higher loads well |
| Beeswax | 3% | 6% | 4–5% | Natural honey scent competes with added fragrance |
| Soy/Coconut Blend | 8% | 12% | 10% | Blends often handle slightly higher loads |
| Paraffin/Soy Blend | 6% | 10% | 8–9% | Depends on blend ratio; test both ends |
Worked Examples by Wax Type
Here's how the formula plays out across common batch sizes:
Soy Wax · 8%
Paraffin · 10%
Coconut Wax · 10%
Beeswax · 5%
* Note: Exact wax weight = Total batch weight ÷ (1 + fragrance load %). The Wax & Fragrance Formulator handles this automatically.
Step-by-Step: How to Apply the Formula
- Decide your total batch weight. This is the combined weight of wax + fragrance oil. Work backward from how many candles you're making and the size of each container.
- Choose your fragrance load percentage. Start at the sweet spot for your wax type (see table above). If you've used this fragrance before and know it performs well, you can push toward the upper end.
- Calculate fragrance oil weight. Multiply total wax weight × fragrance load %. Or use the Wax & Fragrance Formulator to do it instantly.
- Check the IFRA maximum usage rate. Every NorthWood fragrance oil has a maximum usage rate listed on its product page. Make sure your calculated amount doesn't exceed it.
- Weigh everything on a kitchen scale. Never measure fragrance oil by volume — density varies and you'll be off every time.
- Add fragrance at the right temperature. For soy wax, add at ~185°F and stir for 2 full minutes to fully incorporate.
- Do a burn test. Fragrance load affects how your wick burns. After any formula change, always burn test before scaling your batch.
What Happens If You Get It Wrong
Too Little Fragrance (Under-fragranced)
- Weak or nonexistent scent throw when burning
- Cold throw (unlit smell) may still be decent, leading to disappointment after lighting
- Customers won't reorder
Too Much Fragrance (Over-fragranced)
- Fragrance oil seeps out of the wax (called "sweating" or "bleeding")
- Poor adhesion to the container — candle pulls away from the glass
- Sooty or smoky burn; wick drowns in the melt pool
- Fire hazard if the pooled fragrance oil ignites
Does Fragrance Load Affect Scent Throw?
Yes — but it's not the only factor. Many makers assume more fragrance = stronger throw. That's partly true, but there are limits:
- Wax type matters more than load. Paraffin naturally throws scent harder than soy at the same fragrance percentage. Coconut wax is a close second.
- Cure time is critical. Soy candles need 1–2 weeks to cure before the fragrance fully bonds. Testing a fresh-poured soy candle will always underperform a cured one.
- Wick size affects throw. A wick that's too small creates a small melt pool and limits how much fragrance vaporizes into the air.
- The fragrance oil itself matters. Some fragrance oils have naturally stronger throws than others. A high-quality fragrance at 8% will outperform a weak one at 12%.
- Room size and air circulation. A candle that "fills the room" in a small bathroom may disappear in an open living area.
Fragrance Load vs. Flash Point — What's the Difference?
These are two different (but related) things beginners often confuse:
- Fragrance load — how much fragrance oil you add, as a % of wax weight. This is what we've been talking about.
- Flash point — the temperature at which a fragrance oil can ignite if exposed to flame. This affects your pour temperature, not your load percentage.
A fragrance with a low flash point (under 170°F) needs to be added at a lower temperature and handled carefully. It doesn't mean you use less of it — it means you watch your thermometer.
Always check both the maximum usage rate and the flash point for every fragrance you use. Both are listed on NorthWood product pages.
Your Free Fragrance Load Calculator
Don't do the math by hand every batch. The NorthWood Wax & Fragrance Formulator does it for you — instantly, for any wax type, container size, and batch count.
- Select your wax type
- Enter your container size (fl oz)
- Set your fragrance load percentage
- Enter batch size (number of candles)
- Get exact wax weight, fragrance weight, and total batch weight — per candle and for the full batch
No account required. Works on mobile. Save your formulas for later.
Quick-Reference Cheat Sheet
| Scenario | What to Do |
|---|---|
| First time with a new wax | Start at the sweet spot % (see table above), cure 2 weeks, then burn test |
| Poor scent throw | Increase load by 1–2%, re-cure, re-test before scaling |
| Fragrance oil seeping / sweating | You've exceeded max load — reduce by 1–2% |
| Changing fragrance oils | Check new oil's max usage rate — always start fresh |
| Scaling from test batch to full batch | Use the same % — the formula scales automatically |
| Blended wax (e.g. soy + coconut) | Use the lower wax's max as your ceiling; test toward the top |
Ready to Formulate?
Use the free NorthWood Maker Tools to calculate your formula, price your candles, and build your scent library — all in one place.
Open the Calculator Shop Fragrance Oils