Convert between Celsius, Fahrenheit, Kelvin, and Rankine
Temperature conversion is essential in science, cooking, weather forecasting, and engineering. This tool provides real-time conversions between the four major temperature scales used worldwide, ensuring you get accurate results whether you're converting for academic research, professional work, or personal use.
Our converter uses the internationally recognized conversion formulas established by scientific organizations, providing results accurate to four decimal places for precision applications while remaining user-friendly for everyday use.
Source: International Bureau of Weights and Measures (BIPM) and International Temperature Scale standards
Precision Note: Our calculator uses the standard conversion factors and rounds results to four decimal places, ensuring high accuracy for scientific and engineering applications while maintaining readability for general use.
Type your known temperature value into any of the four input fields (Celsius, Fahrenheit, Kelvin, or Rankine). The calculator accepts whole numbers, decimals, and negative values where appropriate.
As soon as you enter a value, all other temperature scales will automatically update in real-time. No need to click calculate or press enter - the conversions happen instantly.
Copy the converted values for use in your calculations, reports, or projects. All results are displayed with appropriate precision for scientific and practical applications.
| Scale | Zero Point | Common Uses | Key Characteristics |
|---|---|---|---|
| Celsius (°C) | Water freezing point | Weather, cooking, everyday use | Metric system standard, intuitive for water states |
| Fahrenheit (°F) | Coldest temperature achievable with salt/ice mixture | Weather in US, cooking, body temperature | Smaller degree increments, more precise for weather |
| Kelvin (K) | Absolute zero (no molecular motion) | Scientific research, physics, chemistry | Absolute scale, SI base unit, no negative values |
| Rankine (°R) | Absolute zero | Engineering, thermodynamics | Absolute scale using Fahrenheit degree size |
Accuracy: All conversions are calculated using internationally accepted formulas and displayed to appropriate precision levels.
Scientific Applications: For scientific work, pay attention to significant figures. Our calculator provides high precision, but you should round results based on your measurement accuracy.
Practical Applications: For everyday use like cooking or weather, whole numbers or one decimal place are usually sufficient.
Temperature conversion is a fundamental skill that bridges different measurement systems worldwide. Whether you're a student, chef, or traveler, understanding temperature scales improves communication and precision in your work.
The good news? Temperature conversions use straightforward mathematical relationships that anyone can learn.
Celsius is the most widely used scale worldwide. It's intuitive because it's based on water:
Fahrenheit provides more precise measurements for everyday temperatures:
Kelvin is the absolute temperature scale starting at absolute zero:
Rankine combines Fahrenheit degrees with absolute zero:
0°C = 32°F = 273K
20°C = 68°F = 293K
37°C = 98.6°F = 310K
100°C = 212°F = 373K
Recipe conversion often requires temperature scale changes.
International weather reports use different scales:
Laboratory work often requires conversions between scales.
Manufacturing processes require precise temperature control across different measurement systems.
Celsius to Fahrenheit: Double the Celsius value and add 30 for a quick estimate!
Example: 20°C → (20 × 2) + 30 = 70°F (actual: 68°F)
The most common error is applying only the multiplication without addition/subtraction.
Always identify which scale you're converting FROM and TO:
For precise calculations, avoid rounding intermediate steps.
Your converted result shouldn't be more precise than your original measurement.
If you measure 20°C (two significant figures), your Fahrenheit conversion should be 68°F, not 68.000°F.
Start with memorable reference points and practice with everyday scenarios:
Master these fundamentals, and you'll find applications in countless personal and professional situations.
The formula is: °F = (°C × 9/5) + 32. This means you multiply the Celsius temperature by 9/5 (or 1.8) and then add 32. For example, 20°C = (20 × 9/5) + 32 = 36 + 32 = 68°F.
Science primarily uses Kelvin (K) as it's an absolute temperature scale starting at absolute zero (-273.15°C). Kelvin is the SI base unit for temperature and is essential for thermodynamic calculations. Celsius is also widely used in scientific applications, particularly in chemistry and biology.
Absolute zero is the theoretical temperature at which all molecular motion stops. It equals 0 K (Kelvin), -273.15°C (Celsius), -459.67°F (Fahrenheit), and 0°R (Rankine). This is the coldest possible temperature in the universe.
The United States, Bahamas, and a few other countries use Fahrenheit primarily due to historical reasons and established infrastructure. Fahrenheit provides more precise measurements for weather temperatures (180 degrees between freezing and boiling vs. 100 in Celsius), but Celsius is more intuitive and is used by most of the world.
Our converter uses internationally recognized conversion formulas and provides results accurate to four decimal places. This level of precision is suitable for scientific applications while remaining practical for everyday use. The formulas are based on standards from the International Bureau of Weights and Measures.
No, temperatures cannot be negative in Kelvin or Rankine scales because they are absolute temperature scales that start at absolute zero. If you enter a value that would result in a negative absolute temperature, our converter will indicate this is not physically possible.
Both Kelvin and Rankine are absolute temperature scales starting at absolute zero. The difference is in degree size: Kelvin uses the same degree size as Celsius, while Rankine uses the same degree size as Fahrenheit. This means 1 Kelvin = 1.8 Rankine degrees.
Need More Help? Visit our main conversion calculator page for additional tools and resources, or contact our team for specialized conversion needs.
Accuracy Notice: This temperature converter uses internationally recognized conversion formulas and provides results accurate to four decimal places. While we strive for precision, all calculations are provided for informational and educational purposes only.
Usage Recommendations: For critical applications in scientific research, engineering, medical, or industrial contexts, please verify results with professional-grade instruments and consult relevant technical specifications. The accuracy of any conversion depends on the precision of your input values.
Limitation of Liability: ConversionCalculator.net assumes no responsibility for any errors, omissions, or consequences resulting from the use of this calculator. Users are responsible for verifying the appropriateness and accuracy of conversions for their specific applications.
Educational Purpose: This tool is designed to assist with temperature conversions and provide educational content about temperature scales. It should not replace professional consultation when precise measurements are critical to safety or regulatory compliance.