A wick chart is where testing starts
Every candle supplier publishes a wick chart, and every one of them says the same thing in the small print: test it. The chart was made with one fragrance, one load, no dye and a particular jar. Your candle is different, so the chart can only point you at the right neighborhood. This planner takes the CandleScience chart as that starting point and builds the test you need around it.
How the planner chooses
It finds your jar’s diameter in the chart’s ranges, reads the suggested wicks for your wax, and picks the one in the series you prefer. Then it gives you one size smaller and one size larger in the same series. If your jar falls in the narrow gap between two chart ranges, it picks the smaller range, following CandleScience’s advice for jars between sizes. If the chart only lists double wicks for your size, it shows those and leaves the single-wick test to you.
The chart we use
Starting wicks for each wax by inside jar diameter, from the CandleScience wick guide. “2×” means two wicks.
| Wax | 1.75–2.19 in | 2.2–2.69 in | 2.7–2.94 in | 2.95–3.29 in | 3.3–3.79 in | 3.8–4.2 in |
|---|---|---|---|---|---|---|
| GB 464 | CD 4, ECO 4 | CD 8, ECO 8 | CD 12, ECO 10 | CD 18, ECO 14 | CD 22, ECO 16 | CD 26, 2× ECO 10 |
| GB 444 | CD 4, ECO 4 | CD 10, ECO 10 | CD 14, ECO 12 | CD 20, ECO 14 | CD 24, ECO 16 | CD 26, 2× ECO 10 |
| GB 415 | CD 4, ECO 4 | CD 10, ECO 10 | CD 14, ECO 12 | CD 20, ECO 14 | CD 24, ECO 16 | CD 26, 2× ECO 10 |
| GB 454 | CD 6, LX 12 | ECO 12, LX 20 | CD 18, LX 24 | CD 22 | 2× CD 6, 2× LX 14 | 2× CD 8, 2× LX 16 |
| C-3 | CD 6, ECO 4 | CD 8, ECO 8 | CD 12, ECO 12 | CD 22, ECO 14 | CD 24, ECO 16 | 2× CD 8, 2× ECO 6 |
| IGI 6006 | ECO 1 | ECO 2 | ECO 4 | ECO 8 | ECO 10 | 2× ECO 2 |
| IGI 4630 | LX 12 | LX 14 | LX 18 | LX 22 | LX 24 | LX 26 |
| IGI 4627 | LX 14 | LX 16 | LX 18 | LX 20 | LX 24 | LX 26 |
Running the test
- Pour all test jars from one batch so the only difference is the wick. Label the bottom of each jar with its wick.
- Cure them for the time your wax maker suggests. Soy often needs a week or two to reach full scent throw.
- Burn them side by side, away from drafts, for about four hours. Check at hour one, two and four. Write the melt pool width and the flame height on the burn log.
- Let them cool fully, then burn again. Repeat until each jar is down to about half an inch of wax. The bottom of the jar is where an oversized wick shows itself, with a tall flame and a hot glass.
Reading the results
- Too small: the melt pool never reaches the edge, the candle tunnels and the scent is weak.
- Too big: the flame is tall or flickers, black soot marks the glass, the jar gets very hot and the wick mushrooms heavily.
- About right: a full or nearly full melt pool by the end of a four-hour burn, a calm flame, and a jar you can still pick up near the top.
Never leave a test candle burning unattended, and test on a heat-safe surface. A badly oversized wick can crack glass.
Something else going wrong, like sinkholes, frosting or wet spots? The troubleshooter covers the common problems and which ones a wick change can fix.
Read our guide
How to run a wick test that actually tells you somethingA step-by-step wick test: choosing three sizes, pouring and curing the test jars, the four-hour burn, and how to read melt pools, flames and soot.Questions makers ask
What size wick for a 3 inch jar?
In Golden Brands 464 soy, the CandleScience guide suggests a CD 18 or ECO 14 for a 2.95–3.29 inch jar. In paraffin-soy IGI 6006 it suggests an ECO 8. Those are starting points to test, not answers.
Why test three sizes?
Fragrance, dye, jar shape and even room temperature change how a wick burns. Burning one size down, the chart size and one size up side by side shows which one makes a full melt pool without a big flame or soot.
How long should a test burn be?
CandleScience recommends burning about four hours per session, checking every hour. A good wick reaches a melt pool near the edge of the jar in that time and keeps a steady flame with little soot.
My jar is between two sizes on the chart. Which one?
CandleScience suggests trying the smaller size first. A wick that is too big causes more problems than one that is a touch small.
Do I need to retest if I change fragrance?
Ideally, yes. The chart was tested with no dye and a 7.5% load. Heavy or dark oils, higher loads and dye often need one size up.
Sources we checked
- CandleScience wick guide (charts by wax and diameter)
- CandleScience: CD series wicks
- CandleScience: ECO series wicks
- CandleScience: LX series wicks
Numbers last checked 2026-10-21. How we check them. If your supplier says something different, tell us.