How to Calculate Wax and Fragrance for DIY Candles
Getting the wax and fragrance amounts right is the foundation of a well-made candle. Too little wax and the container won't fill properly; too much fragrance and the wax can't bind it, leading to seeping oil or an unstable flame. This calculator gives you precise amounts based on your container dimensions and wax type.
The 85% fill ratio accounts for wax shrinkage — most waxes contract 10–15% as they cool, leaving a depression around the wick if you fill too full initially. Many candle makers do a second pour at room temperature to fill the dip. Soy wax tends to shrink more than paraffin, so a second pour is especially common with natural waxes.
Fragrance load is typically measured as a percentage of total wax weight. 8% is the most common starting point. Higher loads can overwhelm the wax's binding capacity, causing fragrance to pool on the surface or producing a mushrooming wick. Test different loads to find your ideal scent throw before scaling up production.
Frequently Asked Questions
For soy wax, add fragrance at 130–140°F (55–60°C); for paraffin, at 140–150°F (60–65°C). Too hot and the fragrance evaporates; too cool and it won't bind evenly to the wax.
Wick size depends on container diameter. Containers under 2.5 in need a small wick; 2.5–4 in need a medium; over 4 in may need a large wick or multiple wicks. Always do a test burn before mass production.
Soy candles benefit from 24–48 hours of curing for best scent throw. Paraffin candles are ready in 12–24 hours. On the first burn, let the wax pool reach the edges (2–4 hours) to prevent tunneling.