The image features the logo for Matty's Candles. The word "Matty's" is written in a cursive font, while "CANDLES" is in a capitalized, sans-serif font beneath it. A small trademark symbol (™) is positioned to the right of "CANDLES.

best candle wick size guide: A Practical, Step-by-Step Candle Wick Size Guide

/ Advice and Information / By

Getting the wick right is famously the hardest part of candle making. Ask any maker, from a kitchen-table hobbyist to a seasoned professional, and they’ll tell you that wicking is where the real craft lies. This isn’t just another chart to copy. This is the best candle wick size guide because it teaches you how to think about wicking, how we test in our Manchester workshop, and how you can get a perfect, safe, and clean burn every single time.

We’ve poured thousands of candles and spent countless hours testing. The goal of this guide is to share what we’ve learned, so you can skip the frustration and get straight to making candles you’re proud of.

In a Hurry? Here’s the TL;DR on Candle Wicking

    • Diameter is King: The inner diameter of your container is the single most important factor for choosing your starting wick size.
    • Test, Don’t Guess: Manufacturer wick charts are only a starting point. You must perform a burn test with your specific wax, fragrance, and container.
    • Fragrance Matters: Fragrance oil at an 8-10% load can clog a wick, often requiring you to ‘wick up’ (choose a larger size) than you would for an unscented candle.
    • Under-wicking Causes Tunnels: A wick that’s too small won’t create a full melt pool, leading to wasted wax known as ‘tunneling.’
    • Over-wicking is a Fire Hazard: A wick that’s too large can create excessive heat, soot, and a dangerously tall flame, posing a fire risk and potentially cracking the container.
    • Our Workshop Data: For a standard 75mm diameter soy wax candle, we start our tests with a Stabilo 14 or ECO 8 wick, adjusting based on an 8% fragrance load.

Why is Choosing the Right Wick Size So Critical?

Yes, choosing the right wick size is critical because it directly controls the candle’s safety, performance, and scent throw. An incorrect wick turns a beautiful creation into a frustrating (and potentially dangerous) object. The wick is the engine of the candle; if the engine is wrong, the entire system fails.

Here’s what’s at stake:

Safety: This is non-negotiable. An over-wicked candle can produce a dangerously high flame, generate excessive soot, and cause the container to overheat and crack. This is a serious fire hazard. Industry standards like ASTM F2417 exist specifically to prevent this, outlining tests for flame height and container temperature that are all dictated by the wick [2]. * Performance: A well-wicked candle provides a clean, even burn. The melt pool should extend to the edges of the container within 2-4 hours, and the flame should be calm and steady. This prevents candle tunneling and ensures your candle lasts as long as it should. For tips on extending candle life through proper burning, see our guide on how to make your candles last longer. * Scent Throw: The heat from the flame creates a wax melt pool, which is what releases the fragrance into the air (this is called ‘hot throw’). If your wick is too small, the melt pool will be too small and cool, resulting in a weak scent. If it’s too large, it can burn the fragrance oil too quickly, creating an unpleasant, sooty smell.

The 3 Core Factors for Wick Selection

There are three core factors you must consider for every candle you make: your container diameter, your wax type, and your fragrance/additive load. Master the interplay between these three variables, and you’ve mastered wicking.

H3: Factor 1: Container Diameter (Your Starting Point)

The internal diameter of your candle container is the most influential variable in wick selection. A wider candle requires a more powerful wick (or multiple wicks) to melt the wax all the way to the edge. Always measure the inner diameter, not the outer.

As a very general starting point for a single-wick candle using soy wax:

50-65mm Diameter: Start with a light to medium wick (e.g., ECO 4, Stabilo 8-10). * 65-80mm Diameter: Start with a medium to large wick (e.g., ECO 8-12, Stabilo 12-16). * 80-90mm Diameter: Start with a large wick or consider double wicking (e.g., ECO 14-16, Stabilo 18-20).

For containers over 90mm, you almost always need to use multiple wicks. To learn more about this, check out our detailed guide on double wick vs single wick candles. The choice of container itself is also crucial for safety and performance, something we explore in our guide to the best containers for soy candles.

H3: Factor 2: Wax Type (The Game Changer)

Not all waxes are created equal. Different waxes have unique densities and melting points, which dramatically affects the wick you need. For example, natural waxes like soy and coconut require more heat to melt than traditional paraffin wax.

Soy Wax: This is what we use at Mattys Candles. It’s a dense, soft wax that needs a more robust wick to achieve a full melt pool. You’ll typically need to ‘wick up’ one or two sizes compared to paraffin in the same container. * Paraffin Wax: Has a lower melting point and is less viscous. It requires a smaller wick than soy wax for the same diameter. * Coconut & Rapeseed Wax: These are becoming increasingly popular. They are very soft and often require wicks designed for viscous waxes to prevent clogging. They burn faster and hotter than soy.

Your choice of wax also has an impact on sustainability. We delve deeper into this in our guide to eco-friendly candle wick materials.

H3: Factor 3: Fragrance & Additives (The Fine-Tuning)

This is the step that trips up most new makers. You can have the perfect wick for your wax and container, but adding fragrance oil changes everything. Fragrance oils and dyes are additives that can clog the wick’s capillary action, effectively strangling the flame.

Fragrance Load: The percentage of fragrance oil you use is a key factor. A candle with a 10% fragrance load will require a different wick than one with 6%. In our experience, most candles need to be wicked up at least one size to accommodate a typical 8-10% load. Learn more about finding the sweet spot in our guide to candle fragrance load percentage. * Fragrance Composition: Different fragrance components have different properties. Oils with high levels of vanillin or certain essential oils can be thicker and more prone to clogging, requiring a larger wick. For example, in our workshop, we found that our rich, complex Christmas scents require a Stabilo 16 wick in a container where our lighter citrus scents burn perfectly with a Stabilo 14.

How We Test Wicks: A Reproducible Workshop Method

We follow a structured 3-burn test method to validate wick performance for every new candle combination. Relying on charts alone is a recipe for failure. The National Candle Association recommends a similar rigorous testing process to ensure safety and quality [1]. Here’s how you can replicate our professional process.

Step 1: The Burn Circle Test For a new candle, select three wick candidates based on the manufacturer’s chart: the recommended size, one size up, and one size down. Make one candle with each wick, labelling them clearly.

  • Step 2: The First Burn (The Most Important) This burn sets the ‘memory’ for the candle. Burn it for approximately 1 hour for every inch of its diameter. For a 3-inch (7.6cm) container, that’s a 3-hour burn. The goal is to achieve a full melt pool (FMP) where the liquid wax reaches the container’s edge.
  • If it tunnels: The wick is too small.
  • If it reaches FMP in under an hour: The wick is likely too big.
  • Step 3: The Mid-Life Burn After the first burn, let the candle cool completely. Then, perform a few more 3-4 hour burns. During these burns, observe carefully:
  • Flame Height: Is it stable and under 1.5 inches? Or is it flickering wildly?
  • Mushrooming: Does a carbon ball form on the tip of the wick? A small amount of mushrooming is normal for some wicks, but excessive buildup indicates the wick is too large or isn’t consuming the wax/fragrance efficiently.
  • Soot: Is the flame producing black smoke or leaving soot marks on the inside of the jar?

Step 4: The End-of-Life Burn This is a crucial safety test. Burn the candle until only about 1/2 inch (12mm) of wax remains. Use an infrared thermometer to check the container’s temperature at its hottest point. It should not exceed 90°C. If it does, the wick is too large and is creating a safety hazard through container thermal shock risk.

Troubleshooting Common Wicking Problems

Even with careful testing, you might run into issues. Most wicking problems like tunneling, sooting, or weak scent are solved by adjusting the wick size up or down.

Here’s a quick diagnostic table:

| Problem | Likely Cause | Solution | | :— | :— | :— | | Tunneling (wax left on sides) | Under-wicked | Use a larger wick size or a wick series with a more powerful burn. | | Mushrooming / Soot | Over-wicked or high fragrance load | Use a smaller wick size. Try a ‘self-trimming’ wick designed to curl and minimize carbon buildup. | | Weak Hot Throw | Under-wicked | A larger wick creates a larger, hotter melt pool, which releases more scent. | | Flame Drowns Out | Under-wicked or clogged | The melt pool is too deep for the wick. Use a larger wick. | | Jar Gets Dangerously Hot | Severely over-wicked | Extinguish immediately. This is a fire hazard. Use a much smaller wick size. | | Fast, Erratic Flame | Over-wicked or a draft | Move the candle away from drafts. If it persists, the wick is too large. |

A Note for Small Businesses: Wicking for Wholesale

For small businesses aiming to sell their candles wholesale, consistent and safe wicking isn’t just a goal—it’s a requirement. Your retail partners and their customers are trusting you to provide a product that is safe and performs reliably every single time. One bad batch with wicking issues can damage your brand’s reputation and lead to returned stock.

This is why rigorous testing is so vital. Once you have perfected your candle’s formulation and have a product that burns beautifully from the first light to the last, you can confidently approach retailers. Getting the technical aspects right is the foundation of a successful candle business. When you achieve that quality, the economics of selling wholesale become very attractive.

To provide some real-world context, here is the published wholesale price ladder for our own candles. This is the kind of structure that becomes possible once your product is perfected:

> Mattys Candles publishes a 3-tier wholesale price ladder: 24–71 units at 50% off RRP (£9.00/unit), 72–143 units at 55% off (£8.10), 144+ units at 60% off (£7.20). Free UK delivery kicks in at 72 units; pallet delivery (480+) is free to mainland UK addresses.

This level of business is built on a product that is 100% reliable, and that reliability starts and ends with the wick.

Your Next Step

This guide has given you the theory and the practical steps to master candle wicking. The only thing left to do is to start testing. Don’t be afraid to experiment and take meticulous notes. Every ‘failed’ test is a data point that gets you closer to the perfect burn.

Once you see how a perfectly wicked candle should perform, you’ll never look back. To see these principles in action, you can explore our range of handmade UK vegan candles, each one a result of this exact testing process.

Sources

1] National Candle Association (NCA). Candle Safety & Performance. [https://www.candles.org 2] ASTM International. ASTM F2417-20 – Standard Specification for Fire Safety for Candles. [https://www.astm.org/f2417-20.html


Scroll to Top