Temperature Converter
Convert temperatures between Celsius (C), Fahrenheit (F), and Kelvin (K). Enter a value in any scale to see the equivalent in all three. Includes common reference points like boiling water, body temperature, and freezing point.
Reviewed by the SparkCalc editorial team
How We Calculate This
Conversions use standard formulas: °F = (°C × 9/5) + 32, °C = (°F - 32) × 5/9, K = °C + 273.15. All conversions are mathematically exact.
Sources: BIPM — The kelvin (SI base unit of thermodynamic temperature) · BIPM — The International System of Units (SI Brochure) · NIST — Special Publication 811: Guide for the Use of the International System of Units (SI)
Frequently Asked Questions
How do I convert Celsius to Fahrenheit?
Multiply the Celsius temperature by 9/5 (or 1.8), then add 32. Formula: °F = (°C × 9/5) + 32. For example, 20°C = (20 × 1.8) + 32 = 68°F.
How do I convert Fahrenheit to Celsius?
Subtract 32 from the Fahrenheit temperature, then multiply by 5/9. Formula: °C = (°F - 32) × 5/9. For example, 68°F = (68 - 32) × 5/9 = 20°C.
What is Kelvin used for?
Kelvin is the SI unit of temperature used in scientific contexts. It starts at absolute zero (-273.15°C), the lowest possible temperature. Kelvin is used in physics, chemistry, and astronomy.
What temperature is the same in Celsius and Fahrenheit?
-40 degrees is the same in both Celsius and Fahrenheit. This is the only point where the two scales intersect.
What is absolute zero?
Absolute zero is 0 Kelvin, -273.15°C, or -459.67°F. It is the theoretical lowest temperature where all molecular motion stops. It cannot be physically achieved.
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