Candle Wick Size Guide: How to Choose the Right Wick

Quick Answer

Wick size depends on candle diameter and wax type. General rule: match wick series to wax type (cotton for soy, paper-core for paraffin), then select size based on container diameter. A 3-inch diameter soy candle typically needs a medium CD or ECO wick. Always test multiple sizes.

Why Wick Sizing Matters

The wick is the engine of your candle. Wrong wick size causes:

Too Small (Under-wicked):

• Tunneling (wax left on sides)
• Poor scent throw
• Wick drowning
• Wasted wax

Too Large (Over-wicked):

• Excessive sooting
• Fast burn (short candle life)
• Overheating container
• Fire hazard
• Mushrooming

Getting it right means even burns, optimal scent throw, and safe candles.

Understanding Wick Types

Cotton Wicks (CD, ECO, LX Series)

Best for: Soy wax, coconut wax, natural blends

Paper Core Wicks

Best for: Paraffin, votives, container candles

Rigid center helps wick stay upright. Common choice for paraffin container candles.

Wood Wicks

Best for: Aesthetic appeal, crackling sound

Require specific testing. Sizing differs from cotton wicks.

Zinc/Metal Core

Note: Less common due to environmental concerns. Still used in some applications.

Wick Sizing by Diameter

Soy Wax Container Candles

Paraffin Container Candles

Note: These are starting points. Always test multiple sizes.

Factors That Affect Wick Choice

Wax Type

Different waxes burn differently:

• Soy: Burns cooler, needs larger wicks
• Paraffin: Burns hotter, needs smaller wicks
• Coconut: Similar to soy
• Beeswax: Burns very hot, needs small wicks

Fragrance Load

Higher fragrance loads may need larger wicks. Fragrance affects burn characteristics.

Dye/Color

Heavy dye loads can affect wicking. Dark colors sometimes need slightly larger wicks.

Container Material

Glass retains heat differently than tin or ceramic. May affect wick performance.

Ambient Temperature

Candles burn differently in warm vs. cold rooms. Test in realistic conditions.

The Wick Testing Process

Step 1: Select Test Sizes

Choose 3 wick sizes:

• One smaller than recommended
• Recommended size
• One larger than recommended

Step 2: Make Identical Test Candles

Same wax, fragrance, colorant, container. Only variable is wick size.

Step 3: Conduct Burn Tests

Burn each candle for 1 hour per inch of diameter:

• 3" candle = 3 hour burn
• 4" candle = 4 hour burn

Step 4: Evaluate Results

After burn test, measure:

Step 5: Document and Repeat

Record results. Repeat test if needed with adjusted sizes.

Reading Wick Test Results

Signs of Under-Wicking

Solution: Try next size up.

Signs of Over-Wicking

Solution: Try next size down.

Signs of Correct Wicking

Wick Centering and Preparation

Proper Wick Prep

1. Tab attachment - Secure wick in wick tab
2. Centering - Use wick centering device
3. Straightening - Ensure wick is vertical
4. Priming (optional) - Pre-wax for cotton wicks

Centering Methods

• Wick centering devices (plastic or metal)
• Chopsticks/pencils across container top
• Wick stickers on container bottom
• Hot glue wick tab in place

Multi-Wick Candles

Large candles (4"+ diameter) often need multiple wicks:

Space wicks evenly. Each wick covers its "zone" of the melt pool.

Frequently Asked Questions

Why does my candle tunnel even with the right wick?

First burn matters. Burn until full melt pool forms (3-4 hours). If you extinguish early, wax "remembers" the small melt pool and continues tunneling.

Can I use the same wick for different fragrances?

Test each fragrance. Some scents alter burn characteristics. What works for vanilla may not work for complex blends.

How do I know which wick series to use?

Start with your wax supplier's recommendations. Most soy wax suppliers suggest CD or ECO series. Paraffin suppliers typically recommend LX or paper core.

Why does my wick mushroom?

Some mushrooming is normal. Excessive mushrooming indicates over-wicking or carbon buildup. Try trimming wick to 1/4" before each burn or size down.

Do I need to test wicks for every container?

Yes. Container size, shape, and material all affect burn. A wick that works in one container may not work in another.

How long should I burn test?

Minimum 4 hours per inch of diameter for each test candle. Ideally, burn test through the entire candle to check performance at all levels.

Conclusion

Wick selection is part science, part testing. Charts provide starting points, but only burn testing confirms the right wick for your specific combination of wax, fragrance, colorant, and container.

Document your wick tests carefully. Record what worked and what didn't. Over time, you'll build a reference of proven wick/container combinations for your product line.

Candle making software can help track your testing results and store proven wick combinations with your recipes, ensuring consistent results across production batches.