Fragrance Load Explained: How Much Oil Should You Add to Soy Wax?

One of the most common questions we get from new makers at is: "Why doesn't my candle smell as strong as the ones I buy in the store?"

The immediate instinct is to simply pour more fragrance oil into the next batch. After all, more oil equals a stronger scent, right?

Unfortunately, candle science doesn't work that way. Adding too much fragrance oil is actually one of the fastest ways to ruin a perfect batch of soy wax. To get that room-filling "hot throw" (how a candle smells when it's lit), you need to understand Fragrance Load.

Here is everything you need to know about calculating the perfect amount of oil for your candles.

What is Fragrance Load?

Fragrance load is simply the percentage of fragrance oil in your total candle mixture.

Think of hot, melted wax like a sponge. It can only absorb a certain amount of liquid before it is completely saturated. Every type of wax has a "Maximum Fragrance Load"—usually between 8% and 12%.

If you try to force 15% fragrance oil into a wax that can only hold 10%, the wax sponge is full. The excess oil has nowhere to go, so it will leach out and pool on top of your set candle. This is called "sweating," and it is a major fire hazard because fragrance oil is highly flammable.

The "Maximum" Myth

Just because a wax can hold 12% fragrance oil doesn't mean it should.

In fact, pushing your wax to its absolute limit often results in a candle that burns poorly, smokes, or refuses to stay lit because the wick is drowning in oil. Plus, in the Australian climate—where a warm afternoon can already soften your soy wax—an overloaded candle is much more likely to sweat.

For most premium soy waxes, the "sweet spot" for an incredible scent throw is between 8% and 10%.

The Golden Rule: Weight vs. Volume

Before you calculate anything, you must remember the golden rule of candle making: Always measure by weight (grams), never by volume (millilitres).

Why? Because different liquids have different densities. 100 grams of water takes up a different amount of space than 100 grams of thick, heavy vanilla fragrance oil. If you use measuring cups or ml droppers, your batches will never be consistent. You need a digital scale.

How to Calculate Fragrance Load

To figure out exactly how much oil you need, you use a simple formula:

Let’s look at a real-world example:

Imagine you want to make a single candle that holds 200g of wax, and you want a strong 10% fragrance load.

1. Convert your percentage to a decimal: 10% becomes 0.10.

2. Multiply your wax weight by the decimal: $200 \times 0.10 = 20

3. You need 20 grams of fragrance oil.

Total mixture: You will melt 200g of wax and stir in 20g of fragrance oil, giving you a total candle weight of 220g.

3 Tips for a Stronger Scent Throw

If your math is perfect but your candles still aren't smelling strong enough, check these three variables:

1. Add at the Right Temperature: Always add your fragrance oil when your wax is around 85°C. If the wax is too cool, the oil won't bind to the wax molecules.

2. Stir for 2 Full Minutes: Set a timer! Gently stirring for 120 seconds ensures the oil is completely and evenly dispersed through the melted wax.

3. Let it Cure: Soy wax needs time to rest. Keep the lid on your finished candle and let it sit for 1 to 2 weeks before lighting it. The wait is worth it!

Take the Guesswork Out

Don't want to do the math every time you pour? We’ve got you covered. Check out the free Fragrance Load Calculator on our website to instantly find the perfect ratios for your next batch.

And if you are looking for highly concentrated, premium oils that deliver a massive scent throw at an 8% load, browse the curated fragrance collection at Australian Luxury Candle Supplies today!