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Temperature Converter
Convert Celsius, Fahrenheit, Kelvin and Rankine readings or temperature differences.
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Convert a temperature
Quick values:
All scales
A temperature difference has no zero-point offset: a change of 10°C is a change of 18°F. A reading below absolute zero is not valid.
Runs entirely in your browser. Your files and text are not uploaded.
How to use Temperature Converter
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Step 1: Enter a value
Type a temperature, then choose its current scale and the scale you need.
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Step 2: Choose reading or difference
Turn on temperature difference for a change in temperature rather than a measurement.
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Step 3: Check the steps
Read the result, all four scales and the two conversion steps below it.
Temperature readings and differences
A temperature reading has a zero point. Celsius freezes water at 0 °C, Fahrenheit at 32 °F and Kelvin at 273.15 K. Converting a reading therefore needs both a multiplier and, for some scales, an offset.
A temperature difference is different. A rise of 10 °C is a rise of 10 K and 18 °F or °R. Enable the difference option when you are converting a change rather than a reading.
Common formulas
- °F = °C × 9/5 + 32
- K = °C + 273.15
- °R = °F + 459.67
The calculator rejects physical temperature readings below absolute zero. It runs entirely in your browser.
Limitations
- The body-temperature reference is informational only and is not medical advice.
- Results are numerical conversions; measurement accuracy depends on the original thermometer.
- Temperature differences and readings use different formulas, so choose the correct option.
Frequently asked questions
What is the difference between Celsius and Kelvin?
Their degree size is the same, but Kelvin starts at absolute zero: 0 °C is 273.15 K.
Why is a 10 °C change not 50 °F?
The 32-degree offset applies to readings. A difference of 10 °C equals a difference of 18 °F.
Can a value be below absolute zero?
No. The tool rejects reading values below −273.15 °C, 0 K, −459.67 °F or 0 °R.
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