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Candle Wick Size Calculator

Wick sizing is the single hardest thing to get right when you start making candles. This narrows you to two or three sizes worth testing, and shows you exactly how it got there.

Measure the inside, at the wax line — not the lid or the base.
Typical for the size class. Always measure your own.
The most common container soy in home candle making, and the reference point for most published soy wick charts. Soft, forgiving, prone to frosting.
Published charts are calibrated around 6–8%.
Pigment loads the wick and reduces draw.
Read this before you buy wicks.

Wick charts are starting points for burn testing, never a final answer. Wick performance changes with your specific wax lot, fragrance oil, dye, vessel material and room conditions. Always burn-test a finished candle before selling or gifting it.

Candidates for 2.75" in Soy 464

The highlighted size is the computed starting point. Buy all the sizes shown for that series and burn-test them side by side — the spread is there because published guidance gives a range, not a single answer.

CD · most used
CD-10CD-12CD-14

Self-trimming.

ECO
ECO-6ECO-8ECO-10

Self-trimming.

LX
LX-18LX-20LX-21

Self-trimming.

HTP
HTP-83HTP-104HTP-105

Self-trimming.

HTP has a coarse ladder at this end, so the published "size up for soy" instruction lands on a wick charted for 3.5"–4" — well above your 2.75" vessel. That is what the source prescribes, but finer ladders like CD and LX will give you a closer starting point. Cross-check against those before buying.

Zinc Core

No published size covers this diameter. Several zinc sizes exist in this span (36-24-18Z, 44-32-18Z) but no source in our set publishes their diameter ranges. Omitted rather than interpolated.

Zinc-core wicks are published against paraffin and are rarely used in natural waxes. CD or ECO are the conventional choices for soy.

Wooden wicks

Large (up to 3.25")X-Large (up to 3.5")

Single-ply wooden wicks often fail to hold a full melt pool in 100% soy. Consider a thicker ply or a booster wick.

Why these sizes

Starting from the published chart position for 2.75", the following adjustments were applied:

FactorAdjustmentReason
Soy 464no changeSits at the soy baseline that published charts use.

Series published against a paraffin baseline (CD, LX, HTP, zinc) carry an additional two-step shift when you are pouring soy. ECO is published against soy already, so it takes no shift.

Vessel diameters here are typical for the size class, not guarantees. Nominal capacity describes volume, not width, and the same "8 oz" jar varies between suppliers. Measure the inner diameter of your own container before you buy wicks.

How to test the candidates

The calculator narrows you to two or three wicks. The burn test is what chooses between them — there is no way to skip it.

What you are aiming for: Full melt pool reaching the container wall in 2–4 hours, roughly 1/4"–1/2" deep, with a stable flame and a vessel you can comfortably hold.
  1. Step 1
    Cure before you test

    Let the candles sit at least 24 hours, and ideally a week for soy, before the first burn. Testing a candle that has not cured tells you about a candle nobody will ever light.

  2. Step 2
    Make one candle per candidate wick

    Same wax, same fragrance, same vessel, same pour temperature. The wick has to be the only thing that differs, or you learn nothing about the wick. Label the bottom of each vessel.

  3. Step 3
    Trim to 1/4 inch

    Trim before every burn, including the first. An untrimmed wick mushrooms, soots, and will make a correctly sized wick look over-sized.

  4. Step 4
    Burn 3 to 4 hours and watch the melt pool

    The melt pool should reach the container wall within two to four hours and sit roughly 1/4 to 1/2 inch deep. Reaching the wall much faster means the wick is too large; not reaching it at all means too small.

  5. Step 5
    Check the vessel temperature

    The outside of the container should be warm but safe to pick up. If you cannot hold it comfortably, the wick is too large regardless of how good the melt pool looks.

  6. Step 6
    Repeat for the full burn

    Wick behaviour changes as the wax level drops and the flame sits deeper in the vessel. A wick that is perfect on burn one can drown or overheat on burn five. Test the candle all the way down.

Reading the results

Burn test symptoms and what they mean for wick size
What you seeVerdictWhat to do
Melt pool never reaches the wall; a ring of unmelted wax remainsToo smallSize up. This is tunnelling, and it only gets worse as the candle burns down.
Flame drowns in its own melt pool and self-extinguishesToo smallSize up. The wick cannot draw enough fuel to sustain itself.
Little or no scent when burningToo smallSize up. Hot throw depends on melt pool surface area, so a small pool throws weakly even at a high fragrance load.
Tall, flickering, or dancing flameToo largeSize down. An unstable flame is drawing more fuel than it can cleanly burn.
Visible soot, or black marks up the inside of the vesselToo largeSize down — but first confirm you trimmed to 1/4 inch, since an untrimmed wick soots at any size.
Container too hot to hold comfortablyToo largeSize down. This is a safety failure even if the melt pool looks correct.
Melt pool deeper than about 1/2 inchToo largeSize down. Deep pools overheat the vessel and burn the candle down faster than it should.

How this calculator works

Wick suppliers publish diameter ranges for each size in a series. The catch is that they are not all measured against the same wax: the CD, LX, HTP and zinc charts are published against paraffin, while ECO is published against soy.

So a raw chart lookup is only correct if you happen to be pouring the wax the chart was written for. This tool records which baseline each series uses and converts between them, then applies the documented adjustments for your fragrance load and dye on top. Each of those steps is listed separately in the results, so you can check the working rather than trust the output.

Sources state that soy needs “one to three sizes up” from the paraffin figure. We use two, because that is where our two independent datasets agree exactly — one publishes CD-8 for paraffin at 2.5–3.0″, the other publishes CD-12 for soy at the same diameter, which is two ladder steps apart. The candidate spread either side covers the rest of the stated range.

Start from a common combination

Where these numbers come from

CD, LX, HTP and zinc ranges are published against a paraffin baseline; ECO is published against soy. The engine converts between the two using the documented one-to-three-step soy offset, and both source datasets agree at the overlap.