Candle Wax CalculatorCandle Wick Size Calculator: Match the Wick to the Jar
The wick is the engine of the candle. Too small and the candle tunnels; too big and it smokes, soots, and overheats the glass. Diameter is what decides.
This wick size calculator takes your container's diameter and wax type and returns a starting wick size using published wick charts from wick manufacturers and suppliers — including when to double-wick. Every pick is a starting point: always confirm with a burn test. The calculator itself looks up the ECO and LX charts only; the CD table on this page is a published reference for 464 soy wax, not one the calculator uses.
Wick size calculator
Enter your container's diameter and wax type to get a starting wick size from published wick-manufacturer charts — for a clean, even burn.
How the wick lookup works
Wick sizing is not a formula — it is a lookup against published wick charts, and every result is a starting point for testing, not a final answer. The calculator picks the chart by wax type: Wedo ECO for soy, coconut and beeswax (natural/vegetable waxes), Wedo LX for paraffin — both from Wedo's chart published via Cosy Owl, a Wedo-accredited supplier — and Stabilo CD sizes from Cierra Candles' Container Wick Guide (tested on 464 soy) are shown in the tables below.
The bands are starting points from the published charts: the lower bound of each band is inclusive and the upper bound exclusive, so a diameter never falls in two bands. Gel wax is the exception — standard diameter charts do not cover gel, so the calculator returns zinc-core guidance sized per your gel supplier instead.
Limits: no chart knows your exact candle. Always burn-test the finished, fragranced candle before selling or gifting it.
Candle safety basics
Candles are open flame. Use heat-resistant containers made for candles, never leave a burning candle unattended, keep wicks trimmed to 1/4 inch before every burn, keep the melt pool clear of debris, and follow your wax, wick and fragrance suppliers' guidance. Burn within sight, away from drafts, children and pets.
Limitations of wick charts
No chart knows your exact candle. Fragrance load, fragrance type, dye amount, container shape (a flared tumbler burns differently from a straight jar), and even wick batch variation all move the ideal size. The lookup gets you to the right neighborhood; only a burn test of the finished candle confirms the address.
Double-wicking deserves extra care: two wicks interact, and poor spacing creates hot spots. Keep them evenly spaced and centered, and test the finished candle the same way you would a single-wick one.
Finally, never reuse a chart result across a recipe change. Switching waxes, changing fragrance load, or moving to a different jar means re-testing from the table's starting point.
Diameter-to-wick lookup tables
Natural waxes — Wedo ECO
For soy, coconut and beeswax (natural/vegetable waxes). Source: Wedo (wick manufacturer) chart, published via Cosy Owl (a Wedo-accredited supplier) (chart). Ranges are starting points from the published charts — the lower bound is inclusive, the upper bound exclusive.
| Container diameter | Starting wick |
|---|---|
| Under 1.26 in | ECO 0.5 (50 mm) |
| 1.26 in up to but not including 1.5 in | ECO 0.75 (53 mm) |
| 1.5 in up to but not including 1.97 in | ECO 1 (55 mm) |
| 1.97 in up to but not including 2.24 in | ECO 2 (60 mm) |
| 2.24 in up to but not including 2.48 in | ECO 4/6 (65 mm) |
| 2.48 in up to but not including 2.95 in | ECO 8/10 (70 mm) |
| 2.95 in up to but not including 3.27 in | ECO 12 (75 mm) |
| 3.27 in up to but not including 3.5 in | ECO 14 (80 mm) |
| 3.5 in and over | ECO 16 (80+ mm) |
Paraffin — Wedo LX
For paraffin (also performs well in blends containing vegetable wax). Source: Wedo (wick manufacturer) chart, published via Cosy Owl (a Wedo-accredited supplier) (chart). Ranges are starting points from the published charts — the lower bound is inclusive, the upper bound exclusive.
| Container diameter | Starting wick |
|---|---|
| Under 1.26 in | LX 08 (40 mm) |
| 1.26 in up to but not including 1.5 in | LX 10 (45 mm) |
| 1.5 in up to but not including 1.97 in | LX 12 (50 mm) |
| 1.97 in up to but not including 2.24 in | LX 14 (55 mm) |
| 2.24 in up to but not including 2.48 in | LX 16 (65 mm) |
| 2.48 in up to but not including 2.95 in | LX 18 (75 mm) |
| 2.95 in up to but not including 3.27 in | LX 20 (80 mm) |
| 3.27 in up to but not including 3.5 in | LX 22 |
| 3.5 in up to but not including 3.74 in | LX 24 |
| 3.74 in and over | LX 26 |
464 soy — Stabilo CD
For tested on Golden Brands/AAK 464 soy container wax. Source: Cierra Candles — Container Wick Guide (chart). Ranges are starting points from the published charts — the lower bound is inclusive, the upper bound exclusive.
| Container diameter | Starting wick |
|---|---|
| 1.75 in up to but not including 2.2 in | CD 4 |
| 2.2 in up to but not including 2.7 in | CD 8 |
| 2.7 in up to but not including 2.95 in | CD 12 |
| 2.95 in up to but not including 3.3 in | CD 18 |
| 3.3 in up to but not including 3.8 in | CD 22 |
All chart picks are starting points — confirm with a burn test. Cosy Owl's own guidance: each ingredient and container can slightly affect the wick size you need, so testing is important. Wick series are not interchangeable by number — ECO 10, LX 10 and CD 10 are different wicks.
How to burn-test
From Lone Star Candle Supply's wick guide: pour 2–3 identical test candles differing only by wick size, one step apart in the same series, keeping wax, vessel, fragrance load and dye identical. Cure about a week before testing so the fragrance binds and the wax sets. Run a full first burn — burn until the melt pool reaches the glass, about one hour per inch of diameter (Lone Star; the National Candle Association gives the same one-hour-per-inch rule). Then read the burn: tunneling means size up one step; mushrooming, soot or a tall flickering flame means size down. Trim the wick to 1/4 inch before every burn and keep the melt pool clear of debris. Past about 4 inches of diameter, one wick often cannot pull a full melt pool to the edge — use two or more smaller wicks.
Gel wax
Standard diameter charts do not cover gel. Use zinc-core wicks — they stand straight in hot gel (Wholesale Supplies Plus, quoting Penreco; Candlewic) — trim to less than 1/4 inch above the gel surface, and test-burn in every container before selling or gifting. Never exceed the recommended fragrance percentage for your gel density.
Worked example: a 3-inch soy candle jar
Measure the inside of the jar at its widest point: 3 inches, pouring soy wax. The Wedo ECO chart puts 3 inches in the "2.95 in up to but not including 3.27 in" band, so the starting wick is ECO 12 (75 mm). For 464 soy specifically, the Cierra CD chart gives CD 18 at 3 inches.
Test both side by side in finished, fragranced candles. Run a full first burn — about 3 hours for a 3-inch jar (one hour per inch of diameter) — and check that the melt pool reaches the glass within that time, the flame stays steady with no smoking or mushrooming, and the wick is trimmed to 1/4 inch. If both pass, pick the smaller one — it is safer and the candle burns longer.
The calculator above repeats this lookup for any diameter and wax type.
Related calculators
- Soy Wax CalculatorFree soy wax calculator: enter container diameter, height, and candle count to get wax and fragrance oil amounts in grams, with a worked example.
- Paraffin Wax CalculatorFree paraffin wax calculator: batch wax weight, 15% second-pour reserve for shrinkage, and fragrance oil at 3–10% load.
- Gel Wax CalculatorFree gel wax calculator: batch gel wax weight and safe 0–5% fragrance loads.
Start from the candle wax calculator to find a different tool.
Frequently asked questions
What do wick names like CD 18 and ECO 14 mean?
They name the wick series and the size number, which roughly tracks the wick's thickness. A higher number means a bigger flame and a wider melt pool. CD, ECO and LX are different manufacturers' series — the same number means nothing across series (ECO 10, LX 10 and CD 10 are different wicks).
What happens if my wick is too small?
The flame cannot melt wax all the way to the container walls, so the candle tunnels — a narrow hole burns down the middle while a ring of unmelted wax stays stuck to the glass. The candle looks bad, wastes wax, and the flame can drown in its own melt pool.
What happens if my wick is too big?
An oversized wick makes a tall, smoky flame, overheats the container, and grows a mushroom-shaped carbon cap that drops soot. In the worst case it can crack the glass from excess heat. If your candle smokes or the flame dances wildly, size down.
When should I use two wicks instead of one?
When the container is wider than about 4 inches. No single wick can melt a pool that wide without becoming dangerously large itself. Space two smaller wicks evenly — roughly at the one-third and two-thirds marks across the diameter.
Does the fragrance I add change the wick size?
It can. Heavy fragrance loads and certain fragrance oils burn differently enough to shift the ideal wick a size up or down. That is why burn-testing uses the finished, fragranced candle — never test with plain wax and assume the result carries over.
Can I just guess and skip burn testing?
No — always burn-test. The chart pick is a starting point: pour a test candle, cure it, and burn it fully before committing to a batch — whether it is for yourself, a gift, or a sale. Wick series, wax, fragrance, dye, and jar shape all nudge the ideal wick, and only a burn test of the finished candle confirms it.
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