Temperature Converter
Convert between Celsius, Fahrenheit, and Kelvin scales instantly.
Frequently Asked Questions
Why do different countries use different temperature scales?
The Fahrenheit scale was developed in 1724 and became prevalent in English-speaking countries, particularly the US. The Celsius scale (originally Centigrade) was created in 1742 and adopted internationally due to its simpler base-10 system. Kelvin is the scientific standard used in physics and chemistry.
What is absolute zero and why can't it be colder?
Absolute zero (0 Kelvin or -273.15°C) is the lowest possible temperature in the universe. At this point, all atomic motion stops. It's the theoretical limit defined by thermodynamic laws—temperatures cannot go below this point because there are no more particles to remove energy from.
Why is Kelvin used in science instead of Celsius or Fahrenheit?
Kelvin is used in science because it's an absolute scale starting at absolute zero, which makes it ideal for calculations in physics and chemistry. It doesn't have negative values, making mathematical relationships cleaner and more intuitive for scientific work.
Is there a temperature where Celsius and Fahrenheit are equal?
Yes! At -40 degrees, Celsius and Fahrenheit scales intersect. So -40°C equals -40°F. This is the only point where the two scales show the same numerical value.
How accurate is body temperature at 98.6°F?
Normal human body temperature averages 98.6°F (37°C), but it naturally varies from about 97°F to 99°F depending on time of day, location measured, and individual differences. Morning temperatures are typically lower than afternoon temperatures, and temperature can vary by location (mouth, ear, armpit, etc.).