Multi-Container Candle Fill Calculator
Calculate the exact wax weight and fragrance oil needed to fill multiple candle containers of different sizes.
Why you cannot just fill containers with liquid wax:
Wax shrinks as it cools — typically 5–10% by volume depending on the wax type. If you pour the exact container volume in liquid wax, you will get sinkholes and uneven tops. You must account for shrinkage and plan a second (relief) pour.
Wax density and volume conversion:
Different waxes have different densities when solid:
| Wax Type | Density (lb/cu in) | Pour Temp (°F) | Shrinkage |
|---|---|---|---|
| Soy (464, Golden Brands) | 0.032 | 120–140 | 5–8% |
| Paraffin (IGI 4630) | 0.034 | 170–180 | 8–12% |
| Coconut blend | 0.031 | 100–120 | 4–6% |
| Beeswax | 0.035 | 145–160 | 5–7% |
| Palm wax | 0.033 | 180–200 | 6–9% |
Container volume formula:
For a cylindrical container:
Volume (oz) = π × (diameter/2)² × height × 0.554 (all measurements in inches, result in fluid ounces)
Wax weight formula:
Wax weight (oz) = Container volume (fluid oz) × wax density factor
Density factors (weight oz per fluid oz): Soy = 0.86, Paraffin = 0.90, Coconut = 0.84, Beeswax = 0.93
Fragrance load:
Fragrance oil (oz) = Total wax weight (oz) × fragrance percentage / 100
Standard fragrance loads:
- Soy wax: 6–10% (most soy waxes max at 10–12%)
- Paraffin: 6–10%
- Coconut blend: 8–12%
Worked example:
Filling 12 jars, each 3" diameter × 3.5" tall, with soy wax at 8% fragrance:
- Volume per jar = π × 1.5² × 3.5 × 0.554 = 13.7 fl oz
- Fill to 90% (leave headroom): 13.7 × 0.90 = 12.3 fl oz
- Wax weight per jar: 12.3 × 0.86 = 10.6 oz
- Total wax: 10.6 × 12 = 127.2 oz (7.95 lbs)
- Fragrance oil: 127.2 × 0.08 = 10.2 oz
- Add 10% extra for waste/spills: wax = 8.75 lbs, fragrance = 11.2 oz
Always melt 10–15% more wax than calculated. Wax sticks to the melting pot, pouring pitcher, and thermometer. You’ll also use extra for the relief pour to fill sinkholes.