When making candles, one of the most important factors to consider is the amount of wax needed. The wax is what holds the shape of the candle and allows it to burn steadily. For an 8 oz candle, you will need approximately 1 cup or 8 oz of wax.
Factors that determine wax needed
There are a few key factors that determine how much wax is required for a candle:
- Candle size – The total volume (in oz or other units) dictates how much wax is needed. An 8 oz candle needs 8 oz of wax.
- Wax density – Paraffin wax weighs about .9 oz per cubic inch. Soy or beeswax is lighter. Wax density must be accounted for.
- Container size – The container shape and dimensions determine how much interior volume there is to fill with wax.
- Number of wicks – More wicks require more wax to surround each one evenly.
- Desired burn time – More wax means a longer burn time.
For a basic 8 oz candle in a straight-sided container, these factors are simple to calculate. The container holds 8 oz of volume, so 8 oz of wax is required. But variables like tapered containers, multiple wicks, or special wax blends can alter the calculations.
Choosing wax type
There are several types of candle wax to choose from:
- Paraffin – A petroleum-based wax that is inexpensive and makes up most commercial candles. It has an average density of .9 oz per cubic inch.
- Soy – Made from hydrogenated soybean oil. Has a lower melting point than paraffin so it’s softer. Density is around .85 oz per cubic inch.
- Beeswax – Harvested from beehives, it has a honey color and aroma. Beeswax density is approximately .96 oz per cubic inch.
- Gel Wax – A mineral oil-based transparent wax used in containers without wicks. It adheres to the container sides well.
- Palm Wax – Derived from palm oil, it is hard and opaque. Density averages .93 oz per cubic inch.
For an 8 oz candle, paraffin or beeswax are good choices since their density is close to 1 oz per cubic inch. Heavier waxes like these help fill the container volume completely.
Calculating wax needed
Let’s walk through the steps to calculate wax needed for an 8 oz candle in a straight-sided container:
- Determine the container dimensions. For example, a container that is 2″ diameter x 3″ tall.
- Calculate the total interior volume of the container. Volume of a cylinder is πr2h. With a 2″ diameter and 3″ height, the volume would be 3.14 x (1″)2 x 3″ = ~11.3 cubic inches.
- Choose wax type and look up density. We’ll use standard paraffin at 0.9 oz per cubic inch.
- Multiply volume by density to get weight. 11.3 in3 x 0.9 oz/in3 = 10.2 oz.
So for an 8 oz candle in a 2″ x 3″ cylinder container, you’d need about 10.2 oz of paraffin wax to fill it adequately.
Adding excess wax
It’s recommended to add a bit more wax than precisely calculated, like 10-15% extra. This helps account for:
- Wax shrinkage – As candles cool and harden, wax can shrink and pull away from container sides.
- Second burns – Extra wax creates a deeper melt pool for longer burn times.
- Tabbing – Excess wax can be used to attach tabbed wicks to the bottom.
With the example above, adding 15% extra wax would mean using about 11.7 oz total instead of 10.2 oz. This helps create an ideal fill level.
Weight versus volume
When measuring wax for candles, you can use either weight or volume units interchangeably since wax density is nearly 1 oz per in3. For example:
- 8 oz weight = about 8 cubic inches volume
- 1 cup volume = approx 8 oz weight
Use a scale for precise weights or graded cups for volumes. Make sure to account for wax density in any volume to weight conversions.
Key takeaways
To summarize calculating wax for an 8 oz candle:
- 8 oz candle = approx 8 oz of wax needed
- Check container dimensions and volume
- Factor in wax type density (paraffin at 0.9 oz/in3 is common)
- Add 10-15% excess wax to account for shrinkage and melt pool
- Use weight (oz) or volume (cups) to measure wax
With the right container measurements and wax density information, calculating the exact wax needed is straightforward. Adding a wax excess buffer helps guarantee even burning and fewer issues. Now you have the core methodology to determine wax quantities for quality candles of any size.
| Candle Size | Wax Needed |
|---|---|
| 4 oz | 4 oz |
| 8 oz (1 cup) | 8-9 oz |
| 12 oz | 12-14 oz |
| 16 oz (1 lb) | 16-18 oz |
This table provides some common candle sizes and the approximate wax needed, taking into account the 10-15% excess wax recommendation.
Conclusion
Figuring out wax requirements for candles is an important step in achieving proper burn and melt characteristics. Start by calculating the precise volume of your container and choosing a wax with a suitable density. Paraffin works well for most candles. Remember to add 10-15% extra wax over the base amount to account for shrinkage and melt pools. With some simple preparation and these calculation steps, you can determine the ideal wax quantity for quality candles in any desired size.