How to use Temperature Converter
Temperature scales use different zero points, so conversion needs an offset as well as a multiplier. Kelvin and Celsius have equally sized increments, while the Fahrenheit increment is smaller.
The calculator converts an absolute temperature rather than a temperature difference. It rejects values below absolute zero, which is 0 K or −273.15 °C. The Kelvin unit is written K, without a degree symbol.
The formula
°F = °C × 9 / 5 + 32
K = °C + 273.15
°C = (°F − 32) × 5 / 9
A worked example
Temperature: 25 · From: Celsius (°C) · To: Fahrenheit (°F)
Converted temperature: 77 °F
Questions about this calculation
Why is Kelvin written without a degree sign?
Kelvin is the SI unit name and its symbol is K, not °K.
Can I use this for a temperature increase?
This converts absolute temperatures. For differences, do not apply the zero-point offset.
Formula checks: 2026-10-08. Assumptions & corrections.