How much wax do I need to fill a candle container?

Measure your container's volume in ml, multiply by 90% (to leave headspace), then multiply by your wax's solid density (typically 0.86-0.96 g/ml depending on wax type). The result is the wax weight in grams.

What is the maximum fragrance oil percentage for candles?

Maximum fragrance load varies by wax type: soy wax typically holds 10-12%, paraffin 10%, and beeswax only 6%. Exceeding the maximum can cause poor burning, smoking, or safety hazards.

Why should I leave headspace in my candle container?

Leaving 5-10% headspace (filling to 90-95%) prevents overflow during the melt pool, allows room for the wick clip, and gives a cleaner finished appearance. It also helps prevent the glass from overheating near the rim.

Candle Wax & Fragrance Calculator - Free Candle Making Tool

How It Works

Candle making requires precise wax-to-fragrance ratios for both performance and safety. Too little fragrance gives weak scent throw; too much can cause pooling, smoking, or even fire hazards.

This calculator determines exactly how much wax your container holds, then calculates safe fragrance amounts based on your chosen wax type's manufacturer-recommended limits.

The Formulas

Container volume (from dimensions):

Cylinder: π × (diameter÷2)² × height ÷ 1000 (mm to ml)
Rectangular: length × width × height ÷ 1000

Wax weight:

Usable volume = Container volume × Fill factor (typically 90%)
Wax weight (g) = Usable volume (ml) × Wax solid density (g/ml)

Fragrance weight:

Fragrance (g) = Wax weight × Fragrance percentage ÷ 100

Safety Thresholds

Each wax type has a manufacturer-specified maximum fragrance load:

Soy wax: 10-12% depending on brand
Paraffin: 10%
Beeswax: 6%
Coconut wax: 12%

The calculator uses a traffic-light system: green (safe), yellow (approaching limit), red (exceeding limit). Exceeding the maximum doesn't block input — experienced chandlers may intentionally push limits with specific wax-fragrance combinations they've tested.

How to Use This Calculator

Select your wax type from the preset list
Enter container size:
- Toggle "Enter volume directly" if you know the ml
- Otherwise select container shape and enter inner dimensions in mm
Adjust fill level — 90% is standard (leaves room for wick clip and clean appearance)
Set fragrance percentage using the slider — watch the safety indicator
Add dye weight if applicable (most liquid dyes are negligible; block dyes add 1-3g)
Read results and note the pour temperature recommendation
Export PDF as a workshop recipe card

Tips & Safety Notes

Measure inner dimensions of your container, not outer
Density varies by temperature: This calculator uses solid density for weight calculation, which is what matters for purchasing
Hot throw vs cold throw: Higher fragrance load improves hot throw (scent while burning) but too much harms cold throw (scent when unlit)
Cure time: Soy candles need 1-2 weeks of cure time for optimal scent throw. Don't judge fragrance performance on the first day
Wick sizing is not included in this calculator — it requires burn testing. Use your wax supplier's wick guide as a starting point based on container diameter
Flash point: Never heat fragrance oil above its flash point. Add at or slightly below pour temperature

Related Tools

HLB Calculator for Emulsifiers — for makers who also create body products alongside candles
Coffee Extraction Calculator — another precision ratio tool for the detail-oriented maker

FAQ

Why does the calculator show less wax than my container size?

The 90% fill factor accounts for headspace above the melt pool. This prevents overflow, keeps the rim clean, and allows room for the wick clip. You can adjust this to 95-100% for specific designs.

Should I measure wax by weight or volume?

Always by weight. Wax density varies between solid and liquid states, and between brands. Weighing on a kitchen scale (accurate to 1g) gives consistent results batch to batch.

What happens if I exceed the maximum fragrance load?

Possible issues include: fragrance oil pooling on the surface, excessive smoking when lit, mushrooming wicks, and in extreme cases, the wick flame can ignite the pooled oil. Start at 6% and increase in 1% increments with testing.

Last reviewed: June 2026