The water-fill method plus correct fragrance-load math, so a batch comes out to the gram instead of a guess. Ounces and grams side by side.
Fill to your pour line with water, weigh it (tare the vessel)
Fragrance load is measured against wax weight, not total weight — the convention wax manufacturers use for their rated maximums. This calculator does that math correctly, which is why its wax number is slightly lower than calculators that ignore the fragrance's share of the fill.
Container sizes are marketed by nominal volume, but your pour line, the vessel's true shape, and headspace all vary. Weighing a water fill measures your exact container the way you actually use it. Wax is about 86% as dense as water, so the wax-plus-fragrance fill weighs about 0.86× the water weight — the factor this calculator applies.
If the container holds F ounces of fill and your load is L (as a fraction of wax weight), then wax = F ÷ (1 + L) and fragrance = wax × L. At an 8% load in an 8 oz-water container: fill ≈ 6.88 oz, wax ≈ 6.37 oz, fragrance ≈ 0.51 oz. Skipping this division and taking 8% of the total is a small but real overdose of fragrance in every candle.
Weigh fragrance separately and stir it in at the temperature your wax manufacturer specifies — commonly around 180–185°F for soy — stirring gently for a couple of minutes so it binds rather than pooling. Adding it too hot burns off top notes; too cool and it won't incorporate.
Not the amounts, but it's the other half of a candle that works. Wick sizing depends on container diameter, wax type, and fragrance load, and realistically requires test burns. Treat wick charts as starting points, not answers.