# How long candles last

## Burning time of candles - calculator

Burning time: candles | Mixed wax | Rectangular candles

Calculate how long a candle of a certain size or weight can burn or how long it takes to burn down a certain length. It is assumed that the candle has the shape of a cylinder and burns down completely without leaking. For candles that burn down in the middle and leave a wax rim, this calculation is not correct. The wick must be shortened to normal length regularly if it does not burn down by itself, because a long wick sucks in more wax and thus ensures faster burning. Most modern candles are made of paraffin wax.

The weight can be calculated from the length, diameter and the type of wax, but you can also enter the weight directly. The length to be entered is either the height of the whole candle or the length of the piece that should burn down. The diameter is that of the base of the cylindrical candle. If the candle has a different shape, the weight must be entered. Rolled beeswax candles made of honeycomb have a lower weight because they contain air pockets, the weight must also be entered for these. The calculated approximate burning time is a good estimate of the maximum time a candle will burn, an ideal value, but not an exact figure. In practice, the burning time is usually a little shorter. Wind, additives in the wax, wick length and other factors can influence the burning time.

Commercial candles are generally made largely of one of three different types of wax:
Paraffin wax Made from crude oil, it is the cheapest of the three, slightly lighter than the others and burns the fastest. If a candle is not specified which wax it is made of, then it is almost certainly paraffin wax.
stearin is obtained from vegetable or animal fat, nowadays mostly from palm oil, for which rainforests are cut down. Therefore, stearin candles should be labeled as organic or with RSPO. Stearin is more stable and less sooty than paraffin wax, it burns a little longer and is a little more expensive.
Beeswax is a natural wax and the original material for making candles. It is yellow in color, burns only about half as fast as paraffin wax and smells pleasant. It's a lot more expensive, so it's used less often for candles.

The following values ​​are used for calculation:
densityBurn rate
Paraffin wax0.90 g / cm³7.5 g / h
stearin0.93 g / cm³6.5 g / h
Beeswax0.95 g / cm³4.0 g / h