Our online temperature converter is designed for quick and accurate results, supporting all key scales: Celsius, Fahrenheit, Kelvin, and Rankine. Whether you're a student, chef, scientist, or traveler, this temp converter simplifies the process of switching units. Just input your value, select your scales, and get a precise result instantly, eliminating manual calculation errors.
Using our temp conversion tool is a simple, three-step process that guarantees accuracy:
Choose Your Input Scale: Select the unit of the value you are starting with (e.g., Celsius).
Choose Your Target Scale: Select the unit you wish to convert the temperature to (e.g., Fahrenheit).
Enter the Value: Type the numerical value into the temperature converter field.
The tool automatically applies the correct mathematical formula and displays your converted result in a fraction of a second.
Essential Temperature Converter Formulas
While our calculator handles the math for you, understanding the core formulas can be insightful. Here are the fundamental equations for converting temperature:
Celsius to Fahrenheit: °F = (°C × 9/5) + 32
Fahrenheit to Celsius: °C = (°F - 32) × 5/9
Celsius to Kelvin: K = °C + 273.15
Kelvin to Celsius: °C = K - 273.15
These standardized formulas are the foundation of every precise temperature conversion.
The existence of multiple scales is a result of rich historical development across different regions and scientific needs.
Celsius (°C): Established in 1742 by Swedish scientist Anders Celsius. It is a centigrade scale, based on 100 degrees between the freezing and boiling points of water.
Fahrenheit (°F): Developed by German physicist Daniel Gabriel Fahrenheit in the early 18th century. For quick conversions, many rely on a Celsius to Fahrenheit converter.
Kelvin (K): The base SI unit for thermodynamic temperature, established by Lord Kelvin. It is an absolute scale that starts at absolute zero (0 K).
Rankine (°R): An absolute temperature scale similar to Kelvin but using the Fahrenheit degree increment. It is primarily used in specific engineering fields in the United States.
How do I figure out Celsius from Fahrenheit mentally?
For a rough estimate, you can subtract 30 from the Fahrenheit temperature and then divide by 2. This will bring you close to the Celsius value. Take 70°F: a quick estimate gives (70 − 30) ÷ 2 = 20°C, whereas the true value is 21.1°C.
Why is the conversion factor 1.8 (or 9/5)?
The factor 1.8 is derived from the ratio of degree sizes. On the Fahrenheit scale, there are 180 degrees between water’s freezing and boiling points (32°F to 212°F), while the Celsius scale has 100. Dividing 180 by 100 yields 1.8, meaning every 1°C change equals a 1.8°F change.
Is 40 degrees Celsius equal to 100 degrees Fahrenheit?
No, this is a common misconception. 40°C is equivalent to 104°F. Conversely, 100°F is approximately 37.8°C. Our temp conversion tool can help you avoid this common mix-up.
What is absolute zero on different scales?
Absolute zero is the coldest possible temperature. It is defined as:
- 0 Kelvin (K)
- -273.15°C
- -459.67°F
- 0°R (Rankine)