How to Choose the Right Wick: A Candle Maker's Wick Guide
The right wick is the one that passes your burn test, and this guide shows you how to find it. A chart can point you to a starting size, but no chart knows your wax, your fragrance, or your vessel.
The wick is the engine of your candle. Too small and it tunnels, wasting wax and scent. Too big and it smokes, soots, and overheats the vessel. Get it right and you get a full melt pool, a steady flame, and a strong hot throw.
Below you'll find what affects wick size, the most common wick types, a starting-point chart, and the exact burn test I use for every Aura Aligned candle.
What affects wick size
Vessel diameter matters most, but five things work together. Change any one and your wick may need to change too.
- Vessel diameter. Measure across the inside of the vessel at its widest point. The wider the vessel, the bigger the wick, or the more wicks.
- Wax type. Soy and other natural waxes are dense and melt slowly, so they usually need a larger wick than paraffin or blends. Coconut blends melt easily and often need a smaller one.
- Fragrance load. More fragrance oil changes how the wax burns. A wick that works at 6% may soot at 10%. Some heavy oils, like vanilla and cinnamon, burn hotter.
- Dye. Dye can clog a wick over time. If you use a lot of color, you may need to size up.
- Vessel material. Glass, tin, ceramic, and concrete all hold heat differently. Thick vessels like concrete absorb heat, so the melt pool can take longer to reach the edges. Always test in the exact vessel you sell.
Common wick types
Each wick series burns differently, so a size in one series doesn't match the same number in another. Pick a series that suits your wax, then size within it.
| Wick series | Material | Best for | Good to know |
|---|---|---|---|
| ECO | Cotton with paper threads | Soy and natural waxes | Clean, steady burn; curls to reduce mushrooming |
| CD | Cotton with paper threads | Soy, viscous waxes | Self-trimming; handles heavy fragrance and dye |
| HTP | Cotton with paper threads | Soy, paraffin, blends | Burns hotter; good for wide vessels |
| LX | Flat braided cotton | Paraffin, blends | Very stable flame; less mushrooming |
| Wooden | Wood, single or layered | Soy, coconut blends | Crackle and wide flame; trickier to dial in |
Wick makers publish their own size charts, so check your supplier's chart for the series you buy.
Starting-point chart
Use these sizes as a place to start testing, not a final answer. They assume soy wax at about 6–8% fragrance in a glass or tin vessel.
| Inside diameter (in) | ECO series | CD series | Notes |
|---|---|---|---|
| 2.0 | ECO 2–4 | CD 5–8 | Small jars and tins |
| 2.5 | ECO 4–6 | CD 8–10 | Common for 4–6 oz jars |
| 3.0 | ECO 6–8 | CD 10–12 | Common for 8–10 oz jars |
| 3.5 | ECO 8–12 | CD 12–16 | Test one size up and down |
| 4.0+ | Two wicks | Two wicks | Two smaller wicks melt more evenly than one large one |
Test three wicks at once: the suggested size, one size smaller, and one size larger. For thick vessels like concrete, start toward the larger end.
How to run a burn test
A burn test takes a few days, but it saves you from selling a candle that tunnels or smokes. Never leave a test candle unattended.
- Make three test candles. Same wax, fragrance, dye, and vessel. Change only the wick size. Label each one.
- Let them cure. Give soy candles at least 48 hours, ideally a week or two, before burning.
- Trim to 1/4 inch and light all three at the same time, away from drafts.
- Burn for 1 hour per inch of diameter. A 3-inch candle burns about 3 hours. Check every 30 minutes.
- Record what you see: flame height, melt pool width, smoke or soot, and the vessel temperature.
- Let them cool fully, then repeat. Test at least three or four burns, including one near the bottom.
You're looking for a full melt pool that reaches the edges within that burn time, a calm flame about 1 inch tall, no black smoke, and a vessel that's warm but safe to touch.
Reading your results
Most problems point to a wick that's too small or too big. Match what you see to the fix.
| What you see | Likely cause | Try this |
|---|---|---|
| Tunneling, wax left on the sides | Wick too small, or burns too short | Size up; burn longer on the first light |
| Melt pool too deep (over 1/2 in) | Wick too big | Size down |
| Flame over 2 in or flickering | Wick too big, or untrimmed | Trim to 1/4 in; if it continues, size down |
| Black smoke or soot on the glass | Wick too big, or heavy fragrance | Size down or lower fragrance load |
| Mushrooming (carbon ball on the tip) | Wick too big, or heavy fragrance or dye | Size down or try a self-trimming series |
| Flame drowns or goes out | Wick too small, or clogged with dye | Size up or reduce dye |
| Vessel too hot to touch | Wick too big | Size down; thick vessels need extra care |
If every size in one series fails, switch series rather than keep adjusting.
Still stuck?
Wicking takes patience, and every candle maker goes through a few failed tests. That's part of the craft.
For more tips, watch my Candle Making Tips video series, and leave a comment with the topics you want me to cover next. You can also find all my guides on the Candle Making Resources page.
If you'd like hands-on help, book a 1:1 candle making session with me. In 30 minutes, we'll look at your wax, fragrance, vessel, and test results together and get your candle burning the way it should.
