Temperature Converter
Convert between Celsius, Fahrenheit, Kelvin, Rankine, and Réaumur all at once. Just enter a value and pick its unit to see the full conversion table.
Last updated:
Input
Input unit
Celsius（℃）
Result
In Celsius (℃)
25℃
| Unit | Symbol | Converted value |
|---|---|---|
| Celsius | ℃ | 25 |
| Fahrenheit | ℉ | 77 |
| Kelvin | K | 298.15 |
| Rankine | °R | 536.67 |
| Réaumur | °Ré | 20 |
How it works
- Five units are supported: Celsius (°C), Fahrenheit (°F), Kelvin (K), Rankine (°R), and Réaumur (°Ré).
- Celsius (°C) is used as the base unit. Your input is first converted to Celsius and then to every other unit, which keeps all results consistent.
- Temperature scales differ not only in the size of each degree but also in where their zero point sits, so this tool uses a dedicated formula for each unit rather than the simple ratio used for length or weight.
- To use it, just enter a number and pick its unit. The Celsius value is shown prominently, and the table below lists the result in every unit at the same time.
- Results are rounded to about six decimal places, switching to exponential notation when the magnitude is very large or very small. Keep the rounding in mind when you need exact values.
- As a handy reference, water freezes at 0°C (32°F, 273.15 K) and boils at 100°C (212°F).
Frequently asked questions
- What is the formula to convert Celsius to Fahrenheit?
- Multiply the Celsius value by 9/5 and add 32 (°F = °C × 9/5 + 32). Because temperature scales differ in both their spacing and their zero point, the tool applies a dedicated formula per unit rather than a simple ratio.
- How do Kelvin, Rankine, and Réaumur differ from Celsius?
- Kelvin starts at absolute zero, so 0°C = 273.15 K; Rankine is the absolute scale tied to Fahrenheit degrees; and Réaumur puts water's freezing at 0 and boiling at 80. All five scales convert simultaneously through a Celsius base.
- At what temperatures does water freeze and boil in each unit?
- Water freezes at 0°C (32°F, 273.15 K) and boils at 100°C (212°F). Results are rounded to about six decimal places, switching to exponential notation for extreme values.
Reviews
Tell us what you think of this calculator.
Write a review
Found an incorrect result or a problem? Turn this on to report it.
Rating