Conversions between temperatures with this tool, particularly beyond two or three decimal places, are not meant to be precise by modern standards and should be taken with a grain of salt. Some scale names have been transliterated.
Many of the scale listed are considered now rare and obscure, but were popular back in the 1700s and 1800s. Some of these are still used. For instance, from time to time
the Reaumur scale is still used among European cheesemakers.
the Rankine scale can be found in the engineering literature.
the Gas Mark, Stufe, and Thermostat scales appear on some kitchen ovens in England, Austria, and France, respectively.
In the Netherlands the Reaumur scale is used when cooking sugar syrup for desserts and sweets.
The Gas Mark is still popular and used on gas ovens and cookers in Great Britain, Ireland and some Commonwealth of Nations countries.
When changing units, you may want to follow NIST guidelines (NIST, 2006) for expressing results to a given number of significant digits:
If the first significant digit of the converted value is greater than or equal to the first significant digit of the original value, round the converted value to the same number of significant digits as there are in the original value.
If the first significant digit of the converted value is smaller than the first significant digit of the original value, round to one more significant digit.