How Much Fragrance Oil to Add to Candle Wax

The math, step by step

The formula is short: oil weight = wax weight × load. Write the load as a decimal, so 6% becomes 0.06. Use the same unit on both sides, ounces or grams, and weigh on a scale. Never use cups, teaspoons or fluid ounces. Fluid ounces measure space, not weight, and an oil and a wax do not weigh the same per spoonful.

Example: you are pouring 16 oz of wax at 8%. That is 16 × 0.08 = 1.28 oz of oil. The load is the same percentage whether the candle is small or large. A bigger candle simply needs more oil in total.

These are arithmetic examples. They are not a recommended load for your wax.

If you know the finished fill weight instead

Sometimes you start from the weight you want in the jar, wax and oil together. Because load is measured against the wax, you cannot take 6% of the fill. Work backwards instead.

1. Divide the target fill weight by 1 plus the load as a decimal. For 6%, divide by 1.06. This gives the wax weight.
2. Multiply that wax weight by the load. This gives the oil weight.
3. Check: wax plus oil should equal your target fill.

Example: a 10 oz fill at 6%. Wax is 10 ÷ 1.06 = about 9.43 oz. Oil is 9.43 × 0.06 = about 0.57 oz. Together, 10 oz. The Fragrance Load Calculator does both directions for you.

How much your wax allows

General advice from suppliers is 6–10% of wax weight for candles. That range is only a rough guide. Each wax maker states its own limit, and the limits differ by product:

Beeswax is the outlier. Suppliers say it holds less fragrance than other waxes, and one supplier lists no fragrance capacity for it at all, suggesting essential oils for all-natural beeswax candles instead. Follow your product’s own sheet.

Why more oil is not always a stronger candle

It feels logical: more oil, more scent. But wax can only hold so much. The National Candle Association says there is a maximum amount of fragrance a candle can carry before it stops burning cleanly or properly. Suppliers describe the signs of too much oil: oil seeping or pooling on the surface, a weak flame, and extra soot.

A common supplier suggestion is to start 1–2 percentage points below your wax’s maximum. If the limit is 10%, begin at 8%. Raise it only if the burn test is clean and the scent needs help. Hot throw also depends on the wick, the melt pool and the cure time, so a weak candle is often a wick or cure problem, not an oil-quantity problem. See candle scent throw.

Load changes how the candle burns, too. One wick guide suggests going up one or two wick sizes when you use more than about 1 oz of oil per pound of wax (roughly 6%), or a dense oil, or a lot of dark dye. Any time you change the load, test the wick again. The wick size guide explains how.

Blending two or more oils

The load covers all the oil together. If your wax allows 10%, a blend of two oils at 5% each is already at the limit. Choose the total first, then divide it between the oils. Two oils at 8% each would be 16%, far past what any wax in the table above allows.

A simple way to find your load

1. Look up your exact wax’s recommended and maximum load.
2. Pick a starting load a point or two under the maximum.
3. Weigh the wax and the oil separately on a scale and write both numbers down.
4. Add the oil at your wax’s fragrance temperature and stir well. See when to add fragrance oil.
5. Let the candle cure for the time your wax maker suggests. See candle cure time.
6. Finish a full burn test before you judge the scent. Then change one thing at a time.