Temperature converter
Convert between Celsius, Fahrenheit, Kelvin, Rankine and Réaumur, with batch input, decimal precision, the formula used, common reference points and a warning below absolute zero.
Runs in your browserEvery computation happens in your browser — your data never leaves this device.
Result
97.88
Formula：°F = °C × 9/5 + 32
36.697.88309.75557.5529.28Reference points
Matches the standard values exactly, handy for a quick sanity check
| — | °C | °F | K | °R | °Ré |
|---|---|---|---|---|---|
| Absolute zero | °C -273.15 | °F -459.67 | K 0 | °R 0 | °Ré -218.52 |
| Water freezes | °C 0 | °F 32 | K 273.15 | °R 491.67 | °Ré 0 |
| Water boils | °C 100 | °F 212 | K 373.15 | °R 671.67 | °Ré 80 |
| Body temperature | °C 37 | °F 98.6 | K 310.15 | °R 558.27 | °Ré 29.6 |
What this tool does
- Convert Fahrenheit from a foreign recipe, weather report or device manual into Celsius — 98.6 °F is 37 °C.
- Keep temperature units consistent across technical docs and lab notes, with Kelvin, Rankine and Réaumur shown alongside.
- Batch mode: paste a whole column of temperatures, one per line or comma separated, and get the converted list.
- Sanity-check against the reference points: water freezes at 0 °C = 32 °F = 273.15 K and absolute zero is -273.15 °C.
Example
Input
37 Celsius → Fahrenheit
Output
98.6 °F; the same temperature in every unit: 37 °C, 98.6 °F, 310.15 K, 558.27 °R, 29.6 °Ré
The formula is °F = °C × 9/5 + 32. Internally everything goes through Celsius first and then to the target unit, so results match the standard values; anything below absolute zero is rejected.
Frequently asked questions
Why does -300 °C produce an error?
Because a temperature below absolute zero (-273.15 °C) does not physically exist. Every unit has a lower bound: -459.67 °F, 0 K, 0 °R and -218.52 °Ré. Going below one answers with an error and shows that unit’s absolute zero.
Why does a Fahrenheit conversion sometimes give 36.99999999999999?
Floating point multiplication and division leave a tail error. The tool keeps two decimal places by default (adjustable up to ten) and normalises -0 to 0, so 98.6 °F prints as 37 rather than 36.99999999999999.
Does anyone still use Réaumur or Rankine?
Rankine (°R) is still used in parts of US engineering — it shifts the Fahrenheit scale down to absolute zero, so °R = (°C + 273.15) × 9/5. Réaumur (°Ré) is an 18th-century European scale with 0 °Ré at freezing and 80 °Ré at boiling, and now mostly shows up in old literature.
Which separators does batch mode accept?
Line breaks, commas, semicolons, enumeration commas and spaces. If any single value is below absolute zero or is not a number the whole batch fails — problematic rows are not skipped silently.
A conversion disagrees with another site — which is right?
Check the constants each side uses: 273.15 K at freezing and -459.67 °F at absolute zero are the standard values. A site using rounded 273 or -460 will drift. This tool’s reference table matches the standard values exactly, so it is a reliable cross-check.
Keywords：temperature温度换算摄氏celsius华氏fahrenheit开尔文kelvin兰氏度rankine列氏度reaumur绝对零度absolute zero