Science, Tech, Math › Science Convert Temperature from Kelvin to Celsius and Back Share Flipboard Email Print Creativ Studio Heinemann / Getty Images Science Chemistry Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated December 02, 2019 Kelvin and Celsius are two temperature scales. The size of the "degree" for each scale is the same magnitude, but the Kelvin scale starts at absolute zero (the lowest temperature theoretically attainable), while the Celsius scale sets its zero point at the triple point of water (the point at which water can exist in solid, liquid, or gaseous states, or 32.01 F). Converting between the Kelvin and the Celsius requires only basic arithmetic. Key Takeaways: Kelvin to Celsius Temperature Conversion The equation to convert between Kelvin and Celsius is: C = K - 273.15.While the size of the degree is the same between Kelvin and Celsius, there is no point at which the two scales are equal: A Celsius temperature will always be higher than Kelvin.Celsius temperatures can be negative; Kelvin goes down to absolute zero (no negative temperature). Conversion Formula The formula to convert Kelvin into Celsius is C = K - 273.15. All that is needed to convert Kelvin to Celsius is one simple step: Take your Kelvin temperature and subtract 273.15. Your answer will be in Celsius. The K does not use the word degree or the symbol; depending on the context, generally one or the other (or simply C) is used to report a Celsius temperature. Kelvin to Celsius How many degrees Celsius is 500 K? C = 500 - 273.15500 K = 226.85 C Let's convert normal body temperature from Kelvin to Celsius. Human body temperature is 310.15 K. Put the value into the equation to solve for degrees Celsius: C = K - 273.15C = 310.15 - 273.15Human body temperature = 37 C Reverse Conversion: Celsius to Kelvin Similarly, it's easy to convert a Celsius temperature to the Kelvin scale. You can either use the formula given above or use K = C + 273.15. For example, let's convert the boiling point of water to Kelvin. The boiling point of water is 100 C. Plug the value into the formula: K = 100 + 273.15K = 373.15 About Absolute Zero While typical temperatures experienced in daily life are often expressed in Celsius or Fahrenheit, many phenomena are described more easily using an absolute temperature scale. The Kelvin scale starts at absolute zero (the coldest temperature attainable) and is based on energy measurement (the movement of molecules). The Kelvin is the international standard for scientific temperature measurement, and is used in many fields, including astronomy and physics. While it's perfectly normal to get negative values for Celsius temperature, the Kelvin scale only goes down to zero. Zero K is also known as absolute zero. It is the point at which no further heat can be removed from a system because there is no molecular movement, so there is no lower temperature possible. Similarly, this means the lowest possible Celsius temperature you can ever get is minus 273.15 C. If you ever perform a temperature calculation that gives you a value lower than that, it's time to go back and check your work.