What It Does
The Temperature Conversion Calculator converts a temperature you enter into all three of the most common scales: Celsius (°C), Fahrenheit (°F) and Kelvin (K). Simply type a value, pick the scale it is currently in, and the calculator returns the equivalent in every other scale at once. It works for any temperature — body temperature, weather, cooking, science labs or engineering.
How to Use It
Enter the numeric temperature in the value field, then choose its current unit from the dropdown (Celsius, Fahrenheit, or Kelvin). The result panel shows the equivalent Celsius value as the main figure, with Fahrenheit and Kelvin listed below. Negative numbers and decimals are fully supported.
The Formula Explained
All conversions route through Celsius as a common base. Celsius converts to Fahrenheit with \(\text{F} = \text{C} \times \frac{9}{5} + 32\) and to Kelvin with \(\text{K} = \text{C} + 273.15\). Going the other way, Fahrenheit becomes Celsius via \(\text{C} = (\text{F} - 32) \times \frac{5}{9}\), and Kelvin becomes Celsius by subtracting 273.15. The factor \(\frac{9}{5}\) reflects that one Celsius degree spans 1.8 Fahrenheit degrees, while 32 is the freezing point of water on the Fahrenheit scale. Kelvin shares the same degree size as Celsius but starts at absolute zero (−273.15 °C).
Worked Example
Suppose you enter 100 with the unit set to Celsius — the boiling point of water at sea level. $$\text{Fahrenheit} = 100 \times \frac{9}{5} + 32 = 180 + 32 = 212 \text{ °F}$$ $$\text{Kelvin} = 100 + 273.15 = 373.15 \text{ K}$$ So 100 °C equals 212 °F and 373.15 K.
FAQ
What is absolute zero? Absolute zero is 0 K, equal to −273.15 °C or −459.67 °F — the lowest theoretically possible temperature.
At what temperature do Celsius and Fahrenheit equal each other? They meet at −40°: −40 °C is exactly −40 °F.
Why does Kelvin have no degree symbol? By scientific convention Kelvin is an absolute thermodynamic scale, so it is written simply as "K" (e.g. 300 K), without the ° symbol.
