How To Calculate Wax For Candle Containers

One of the most common mistakes new and experienced candle makers make is assuming the volume directly translates to the amount of wax it can hold. For example many people will buy a 250ml tin assuming it will hold 250g of wax. Wax is actually less dense than water, tins would often end up overflowing. 

The solution is simple: use the 86% Wax Rule

What is the 86% Rule?

The rule: The volume of the container should be multiplied by 0.86 to determine the weight of the wax needed

Why? This rule is accurate for waxes and prevents customers frustration from overflowing and wasted product.

Firstly you need to find out exactly how much liquid the container holds to the safe line. The safe line needs to be determined, if you fill the container all the way up to the brim the lid won’t fit. 

Step 1: Place the empty container on scales

Place your empty container on a set of scales and tare the reading to zero

Step 2: Fill with water

Fill the candle container up with water where you want the wax to stop. Leave enough space at the top for the lid to fit comfortably. 

Step 3: Record the weight

Record the weight in ounces or grams. This will be your ideal water weight for the candle. 

Step 4: Apply the formula

Multiply the water capacity by 0.86 to determine the approximate wax capacity. 

Applying the 86% Wax Rule

To find out how much wax will fit into that exact container, multiply the water capacity by 0.86. 

Water Capacity x 0.86 = wax amount

To determine how much wax your container will hold, first measure its true water capacity by weight. Then multiply that figure by 0.86. This calculation provides an accurate estimate of the total wax.

Should you include fragrance oil in calculations?

This is a common question asked whether fragrance oil should be included when calculating wax weight. The answer is yes. 

The wax calculated using the 86% Wax Rule represents the total weight of the candle, including both wax and fragrance. 

For example:

If your container holds approximately 250g of total candle mixture and you want to use a 10% fragrance load:

Wax weight = 250g ÷ 1.10 = 227g
Fragrance oil = 227g × 0.10 = 23g

This gives you approximately:

227g wax
23g fragrance oil
250g total candle mixture

Using this method helps you avoid overfilling the container while keeping the fragrance load accurate.

This ensures your candle remains within the container's capacity. 

The Science Behind the 86% Wax Rule

Many candle makers are surprised to learn that wax and water don’t weigh the same, even if it’s the same volume. This is because water has a direct relationship between volume and weight. 

Wax is less dense than water, meaning its molecules are not packed as closely together. This is also why wax floats on water. Scientists compare the density of materials using a measurement called specific gravity.

In practical terms, this means that the same container will hold less wax by weight than it would water. A container filled with water may weigh 100 grams, but the same volume filled with wax will typically weigh only around 86 grams. This is the principle behind the popular 86% Wax Rule, which helps candle makers accurately estimate how much wax is needed to fill a container. 

Benefits of using the 86% wax rule

Using this rule can help candle makers:

• Calculate wax requirements more accurately

• Reduce wasted materials

• Avoid overflowing containers

• Improve production

Whether you’re making candles as a hobby or a business, understanding this calculation can save time and money. 

Does the 86% Rule Work for All Waxes? 

The 86% Wax Rule is a guideline for most candle making and works well with many common waxes, including: 

• Soy wax

• Paraffin wax

• Coconut wax

• Rapseed wax 

• Soy-paraffin wax blends

The 86% Wax Rule is one of the most simplified calculations yet most valuable in candle making. Understanding the rule helps eliminate guesswork, reduce waste and ensures your candles are filled correctly every time. 

Before starting your next candle making project, take a few minutes to measure your container and apply the 86% Wax Rule. It’s a small step which can make a significant difference to the quality of your candle making process. 

Now that you know how to calculate wax capacity accurately, choosing the right container becomes much easier. Explore Tinware Direct’s range of candle tins available in a variety of sizes and finishes.

View Tinware Direct's Metal Candle Tins