Temperature Conversion Converter
Our free thermal & energy converter handles temperature conversion conversions. See tables, ratios, and examples for quick reference.
Reviewed by Manoj Kumar, Mathematics Educator
Formula
F = C x 9/5 + 32 | K = C + 273.15 | R = K x 9/5 | Re = C x 4/5
Temperature conversion requires both scaling and offsetting because different scales have different degree sizes and zero points. Celsius-Kelvin differ only by an offset of 273.15. Fahrenheit-Rankine differ by 459.67. Between Celsius and Fahrenheit, both a scale factor (9/5) and offset (32) are needed.
Worked Examples
Example 1: Multi-Scale Scientific Conversion
Problem:A chemical reaction occurs at 450 K. Express this in all temperature scales.
Solution:Celsius: 450 - 273.15 = 176.85 degrees C\nFahrenheit: 176.85 x 9/5 + 32 = 350.33 degrees F\nRankine: 450 x 9/5 = 810 degrees R\nReaumur: 176.85 x 4/5 = 141.48 degrees Re
Result:450 K = 176.85 C = 350.33 F = 810 R = 141.48 Re
Example 2: Engineering Temperature Conversion
Problem:Steam enters a turbine at 1,000 degrees R. Convert to Kelvin and Celsius.
Solution:Kelvin: 1,000 x 5/9 = 555.56 K\nCelsius: 555.56 - 273.15 = 282.41 degrees C\nFahrenheit: 1,000 - 459.67 = 540.33 degrees F
Result:1,000 R = 555.56 K = 282.41 C = 540.33 F
Frequently Asked Questions
What are all the temperature scales?
The main temperature scales are Celsius (used worldwide for everyday measurement), Fahrenheit (used in the US), Kelvin (SI standard for science), Rankine (absolute scale using Fahrenheit degrees, used in some US engineering), Reaumur (historic European scale where water freezes at 0 and boils at 80), and Delisle (inverted scale, now obsolete). Celsius and Kelvin have the same degree size; Fahrenheit and Rankine have the same degree size.
At what temperature are Celsius and Fahrenheit equal?
Celsius and Fahrenheit read the same at exactly -40 degrees. You can verify: F = (-40 x 9/5) + 32 = -72 + 32 = -40. This is the only point where both scales intersect. Above -40, Fahrenheit values are always higher than Celsius. At 0 degrees C (water freezing), Fahrenheit reads 32 degrees. The scales diverge further as temperature increases: 100 degrees C = 212 degrees F, a difference of 112 scale degrees.
What are the most common unit conversion mistakes?
Common errors include confusing fluid ounces with weight ounces, mixing up miles and nautical miles, forgetting that UK and US gallons differ (UK is 20% larger), using the wrong temperature formula, and not accounting for the difference between troy and avoirdupois ounces.
References
Reviewed by Manoj Kumar, Mathematics Educator · Editorial policy