Temperature unit converter — °C, °F, K
Convert temperature between Celsius, Fahrenheit and Kelvin — the quick check for process, motor and insulation specs.
Convert between °C, °F and Kelvin
Formula: °F = °C × 9/5 + 32, K = °C + 273.15. A value at or below absolute zero (−273.15 °C) returns ’--’.
Common reference points (all units)
Quick check: 0 °C = 32 °F = 273.15 K, 20 °C = 68 °F, 100 °C = 212 °F = 373.15 K.
Common process temperatures & motor insulation classes
Motor insulation classes A (105 °C), E (120 °C), B (130 °C), F (155 °C) and H (180 °C) are the common hot-spot temperature limits in IEC 60034-1 / IEC 60085.
Industrial specs mix units — motor insulation (class F = 155 °C) and RTD ranges are usually in °C, HVAC equipment in °F and scientific data in K. AO Ctrl supplies the sensors and probes that read these temperatures.
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Frequently asked questions
What is 25 °C in Fahrenheit and Kelvin?
Using the converter formulas °F = °C × 9/5 + 32 and K = °C + 273.15, 25 °C is 77 °F and 298.15 K. Common checkpoints the tool shows are 0 °C = 32 °F = 273.15 K and 100 °C = 212 °F = 373.15 K.
What temperature limits do motor insulation classes use?
The common hot-spot limits per IEC 60034-1 are class B at 150 °C, class F at 155 °C and class H at 180 °C, shown in the converter as 302 °F / 423.15 K, 311 °F / 428.15 K and 356 °F / 453.15 K. Industrial specs mix units — motor insulation and RTD ranges are usually in °C, HVAC equipment in °F and scientific data in K.
What happens at absolute zero in this converter?
Absolute zero is −273.15 °C, which is 0 K. The converter returns a blank result for any value at or below that point, since negative Kelvin is not physically meaningful. The Celsius-to-Fahrenheit and Celsius-to-Kelvin conversions follow the standard linear formulas above everywhere else.
AO Ctrl provides this tool for reference only.