Calculadora de Temperatura (Celsius, Fahrenheit, Kelvin)
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
F = C×9/5+32 | K = C+273.15
About this calculator
The Temperature Calculator (Celsius, Fahrenheit, Kelvin) allows you to convert between the three most common temperature scales: Celsius, Fahrenheit, and Kelvin. Simply enter a value in any unit and the tool automatically calculates the equivalents in the other two. For example, entering 25 °C gives you 77 °F and 298.15 K. It works using the conversion formulas: from Celsius to Fahrenheit (F = C × 9/5 + 32) and from Celsius to Kelvin (K = C + 273.15).
This calculator is useful in everyday and professional situations. In daily life, when traveling to countries that use Fahrenheit (like the United States), you can quickly convert weather forecasts. In chemistry or physics labs, converting to Kelvin is essential, as it is the absolute scale used in gas laws and thermodynamics. It is also handy for cooks following international recipes with oven temperatures in Fahrenheit.
Important precautions: remember that Kelvin does not use the degree symbol (°), just the letter K. Also, converting from Fahrenheit to Celsius involves a different formula: C = (F - 32) × 5/9. The calculator does this automatically, but it is good to know for verification. For negative values, converting to Kelvin may result in numbers below absolute zero (0 K), which is physically impossible; the tool will display a warning in such cases.
Frequently asked questions
What is the difference between Celsius, Fahrenheit, and Kelvin?
Celsius is based on the freezing (0 °C) and boiling (100 °C) points of water. Fahrenheit has 32 °F as freezing and 212 °F as boiling. Kelvin is an absolute scale, where 0 K is absolute zero (lowest possible temperature), and water freezes at 273.15 K.
How do I convert Fahrenheit to Celsius manually?
Subtract 32 from the Fahrenheit value and multiply by 5/9. Example: 68 °F → (68-32) × 5/9 = 20 °C.
Why doesn't Kelvin use the degree symbol?
Kelvin is an absolute scale, not a relative one. The degree (°) indicates a relative unit, while Kelvin is a fundamental SI unit, represented only by the letter K.
Can I convert temperatures below absolute zero?
No, absolute zero (0 K) is the lower limit of temperature. Values below are physically impossible. If you try, the calculator will display a warning.
Does the calculator work for very high temperatures?
Yes, it accepts any numeric value. For extremely high temperatures, the conversion remains valid, but keep in mind that in practical scales (like ovens) values are limited.