How Do I Calculate My Candle Burn Rate?
There are a couple of different ways to determine a candle's burn time (or burn rate). While either method can be used, we recommend using the first method for more accuracy in approximating a candle's burn time.
Please note: For both of the methods mentioned below on estimating a candle's burn time, we recommend slightly lowering the estimate to account for any remaining wax after the candle has extinguished itself.
Full Burn Test - You can burn the candle in 2 - 3 hour intervals and keep track of how many burns it takes for the candle to completey burn down until it extinguishes itself. For example, if you burned a candle in 2 hour intervals and it took 25 burns to fully burn down, the candle would have an approximate burn time of 50 hours (25 burns * 2 hours each). This method for determining the burn time can be a more lengthy process, but will provide a better estimate of a candle's burn time. If selling candles, we suggest performing this test on at least 2 candles simultaneously to ensure consistent results.
Partial Burn Test (weight method) - Another method for estimating a candle's burn time is by doing a partial burn test. To do this, you need to know how much wax was used in the finished candle to calculate the burn time estimate. Next, follow the steps below:
- Weigh the candle before burning
- Burn the candle for approximately 2 - 3 hours (depending on candle diameter)
- Once the candle cools, weigh the candle again
- Determine the amount of wax used subtracting the weight after burning from the beginning candle weight
- Estimate the total number of burns by dividing the total wax weight used in the candle (not the weight of the candle with container) by the amount of wax used from burning the candle
- Finally, multiply the estimated total burns by the burn time hours. This will provide an estimate of the candle's burn time. See the example below.
- Total wax weight = 12 oz.
- Beginning candle weight = 28 oz. (1 lb. and 12 oz.) - Step 1 above
- Burn candle for 2.5 hours - Step 2 above
- Candle weight after burning = 27 oz. (1 lb. and 11 oz.) - Step 3 above
- Total wax used = 28 oz. - 27 oz. = 1 oz. - Step 4 above
- Estimated burns = 12 oz./1 oz. = 12 burns - Step 5 above
- Estimated candle burn time = 12 burns * 2.5 hours = 30 hours - Step 6 above
This example assumes a test burn time for a container candle. If calculating estimated burn times for free standing candles, the same steps will apply, only you will not need to account for the container weight.
While the partial burn test is a quick way to estimate a candle's burn time, the downfall to using this method is it's accuracy. Candles can have different burning characteristics as they burn down (i.e. the glass gets hotter) and odd shaped containers can skew the results due to varying widths of the candle.