Candle Wick Calculator
Precision sizing for soy, paraffin, and beeswax candles
Measure the internal diameter of your container at its widest point.
Different waxes have different melting points and viscosities.
Standard range is 6% to 10%.
3.10″
Medium-High
Single Wick Recommended
Visual Burn Profile
Yellow area represents estimated melt pool relative to vessel width.
What is a Candle Wick Calculator?
A candle wick calculator is an essential tool for both hobbyist and professional candle makers. It uses physics-based approximations to determine the correct wick size for a specific candle configuration. Unlike a generic calculator, a candle wick calculator accounts for variables like the internal diameter of the vessel, the specific melting point of the wax used, and the percentage of fragrance oils added to the mixture.
Who should use it? Anyone aiming for a clean-burning candle without common issues like tunneling (where the wick burns a hole down the center) or “mushrooming” (where excess carbon buildup occurs on the wick). Misconceptions often suggest that one wick size fits all jars of similar height, but in reality, the width and wax density are the primary drivers of wick performance.
Candle Wick Calculator Formula and Mathematical Explanation
The calculation of the ideal wick involves determining the Effective Burn Diameter (EBD). The formula we use considers the base diameter and adjusts for thermal resistance and fuel load.
The Core Formula:
EBD = D × Wm × (1 + (F – 0.06) × 0.15)
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| D | Vessel Diameter | Inches | 1.5″ – 5.0″ |
| Wm | Wax Multiplier | Factor | 0.9 (Paraffin) – 1.2 (Beeswax) |
| F | Fragrance Load | Decimal | 0.03 – 0.12 (3% – 12%) |
Practical Examples (Real-World Use Cases)
Example 1: The Standard Soy Mason Jar
Imagine you are using a standard 3-inch wide mason jar with 100% soy wax and a 10% fragrance load.
The candle wick calculator would take the 3″ diameter, apply the soy multiplier (approx 1.1), and adjust for the high 10% fragrance load.
The result would suggest a high-performance wick like a CD 18 or an ECO 14 to ensure the melt pool reaches the edges within 3 hours.
Example 2: Small Paraffin Votive
For a small 2-inch votive using paraffin wax and no scent. The candle wick calculator recognizes the lower melting point and narrower diameter, recommending a smaller LX 12 or HTP 41 wick to prevent the flame from becoming too large and hazardous.
How to Use This Candle Wick Calculator
- Measure Your Vessel: Use a ruler to find the internal diameter of your jar. Do not measure from the outside.
- Select Wax Type: Choose the wax that best matches your project. Soy and Beeswax require more heat than Paraffin.
- Input Fragrance %: Enter the percentage of oil you plan to use. Higher loads act as “fuel” and usually require a slightly larger wick.
- Analyze Results: Look at the “Primary Result” for specific series recommendations (CD, HTP, ECO).
- Test Your Candle: Always perform a test burn. Use the calculator as a starting point, as local altitude and humidity can affect results.
Key Factors That Affect Candle Wick Calculator Results
- Vessel Diameter: The single most important factor. Larger jars require wider melt pools, which sometimes necessitates double-wicking.
- Wax Viscosity: Thick waxes like beeswax don’t flow up the wick as easily as paraffin, requiring a “hotter” or thicker wick.
- Fragrance Load: Oils change the combustion chemistry. Over-loading fragrance can clog a wick or cause it to flare.
- Dye Usage: While small, pigments can clog wick capillaries, sometimes requiring a slight step up in wick size.
- Ambient Temperature: A candle burned in a cold room (60°F) will need more heat than one burned in a warm room (75°F).
- Altitude: High-altitude candle making often requires smaller wicks due to the decreased oxygen availability for combustion.
Frequently Asked Questions (FAQ)
What happens if I use a wick that is too small?
The candle will “tunnel,” leaving a ring of hard wax on the outside of the jar, wasting wax and significantly reducing scent throw.
What happens if I use a wick that is too large?
The flame will be too high, potentially causing the glass to shatter, producing soot, and causing the candle to burn out too quickly.
What is “mushrooming”?
This is carbon buildup on the tip of the wick. It usually means the wick is drawing more fuel (wax/oil) than it can cleanly burn.
Should I double wick my candle?
If your vessel is wider than 3.5 to 4 inches, our candle wick calculator often suggests double-wicking for an even burn.
How long should a test burn last?
A standard test burn should last 3 to 4 hours, or until a full melt pool is achieved from edge to edge.
Does the color of the wax matter?
Heavily pigmented candles (especially dark colors) can clog the wick. Use our calculator’s results as a base and consider sizing up one step.
What is the difference between CD and HTP wicks?
CD wicks are flat braided cotton with paper threads, great for soy. HTP are high-tension paper core wicks designed to curl slightly, reducing mushrooming.
Can I use this for wood wicks?
This tool is optimized for cotton/paper core wicks, but the melt pool diameter logic applies to wood wicks as well.
Related Tools and Internal Resources
- Candle Making Basics – A complete beginner’s guide to equipment and safety.
- Fragrance Load Chart – Calculate exactly how much oil to add to your wax by weight.
- Wax Melt Guide – Learn about different wax types and their melting points.
- Candle Safety Standards – Ensure your products meet ASTM safety requirements.
- Troubleshooting Tunnelling – Advanced fixes for common burn problems.
- Container Size Guide – Finding the right jar for your target burn time.