Temperature Converter - Free Online Temperature Conversion

How to Use the Temperature Converter

1. Enter value — type the temperature number you want to convert (decimals supported)
2. Select from unit — choose the source temperature scale (Celsius, Fahrenheit, or Kelvin)
3. Select to unit — choose the target scale for conversion
4. Get result — the converted temperature appears instantly
5. Swap units — use the swap button to quickly reverse the conversion direction

Perfect for cooking, weather, science, and travel.

Features

• Celsius, Fahrenheit, Kelvin — supports all three common temperature scales
• Real-time conversion — results update instantly as you type or change units
• Two-way swap — swap source and target units with a single click
• Reference table — includes common reference points (freezing point of water, boiling point, body temperature, absolute zero)
• High precision — results accurate to 2 decimal places
• No data sent — everything runs locally in your browser

Use Cases

• Cooking and baking — convert oven temperatures between Celsius and Fahrenheit when following recipes from different countries
• Travel planning — understand weather forecasts when traveling between countries using different temperature scales
• Science experiments — convert between Celsius and Kelvin for chemistry and physics calculations
• Weather monitoring — compare temperature readings from international weather reports and climate data
• HVAC and thermostat — set your thermostat accurately when the manual uses a different scale

FAQ

How do I convert Celsius to Fahrenheit?

Multiply the Celsius temperature by 9/5 and add 32. For example: 30°C × 9/5 + 32 = 86°F. The converter does this math instantly.

What is absolute zero in Celsius and Fahrenheit?

Absolute zero, the theoretical lowest possible temperature, is -273.15°C, -459.67°F, and 0 K. At this point, molecular motion would theoretically stop completely.

Why does the US use Fahrenheit?

The Fahrenheit scale was developed in the early 18th century and became standard in English-speaking countries. Most of the world adopted Celsius (centigrade) as part of the metric system, but the US maintained Fahrenheit for everyday use.

At what temperature are Celsius and Fahrenheit equal?

-40 degrees. At -40°C, the equivalent temperature is exactly -40°F. This is the only point where the two scales read the same value.

Can I convert negative temperatures correctly?

Yes. The converter handles negative temperatures on all three scales correctly. For example, -10°C converts to 14°F and 263.15 K.

Tips

• For approximate conversions, remember: Celsius to Fahrenheit ≈ double it and add 30 (rough, for weather temps)
• Water freezes at 0°C / 32°F / 273.15 K and boils at 100°C / 212°F / 373.15 K at sea level — useful mental reference points
• Room temperature is approximately 20-22°C (68-72°F)
• When cooking, a 350°F oven equals about 175°C — the most common baking temperature
• Kelvin has no negative values and is used primarily in scientific contexts — 0 K is absolute zero