Candle Wick Size Calculator
Find the correct wick size for your candle container based on diameter and wax type.
Avoid tunneling, sooting, and uneven burns.
Why wick sizing matters:
The wick is the single most important variable in candle making. A wick that is too small creates tunneling — the wax melts only in a narrow channel around the wick while the outer edges stay solid. A wick too large produces excessive soot, a tall flickering flame, and burns through wax too fast.
The golden rule: The melt pool should reach the full diameter of the container within 1–2 hours of the first burn. This is called a “full melt pool” and prevents tunneling on all subsequent burns.
Wick sizing depends on three things:
- Container diameter — wider containers need larger wicks
- Wax type — soy wax has a lower melt point and needs a hotter wick than paraffin
- Fragrance and dye load — heavy loads can clog the wick, requiring a size up
General wick size chart (cotton core, flat braid):
| Container Diameter | Soy Wax | Paraffin |
|---|---|---|
| 2.0–2.5 in (50–65 mm) | ECO-1 or CD-3 | LX-10 or CD-2 |
| 2.5–3.0 in (65–76 mm) | ECO-4 or CD-5 | LX-12 or CD-4 |
| 3.0–3.5 in (76–89 mm) | ECO-8 or CD-8 | LX-14 or CD-6 |
| 3.5–4.0 in (89–102 mm) | ECO-10 or CD-12 | LX-16 or CD-8 |
| 4.0+ in (102+ mm) | Double wick recommended | LX-18+ or double wick |
Worked example:
A 3-inch (76 mm) diameter jar with soy wax and 8% fragrance load:
- Start with ECO-8 or CD-8
- Heavy fragrance may require sizing up to ECO-10
Testing protocol: Always burn-test a new combination. Light the candle and check at 1 hour and 2 hours:
- Full melt pool in under 2 hours = correct wick
- Tunneling after 2 hours = wick too small, size up
- Flame taller than 1.5 inches or sooting = wick too large, size down
Double wicking: Containers wider than 4 inches benefit from two smaller wicks spaced evenly, rather than one oversized wick. This gives a more even melt pool and cleaner burn.