Temperature Converter
Convert temperature units like Celsius, Fahrenheit, Kelvin, and Rankine with our fast and accurate Temperature Converter. Ideal for science, weather, cooking, and more.
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How It Works
Understanding Temperature Measurement
Temperature is a physical quantity that expresses the hotness or coldness of matter. It's a measure of the average kinetic energy of the particles in an object, which determines its thermal state. Temperature is one of the most commonly measured physical quantities in science, engineering, and daily life.
Different temperature scales have evolved throughout history, with four primary scales in use today: Celsius (°C), Fahrenheit (°F), Kelvin (K), and Rankine (°R). Each has different reference points and applications across various fields.
Temperature Scales Explained
Celsius (°C)
The Celsius scale, also known as the centigrade scale, is defined by setting 0°C as the freezing point of water and 100°C as the boiling point of water (at standard atmospheric pressure). It's widely used internationally for everyday temperature measurement and in scientific contexts.
Fahrenheit (°F)
The Fahrenheit scale sets the freezing point of water at 32°F and the boiling point at 212°F. It's primarily used in the United States for weather forecasting, cooking, and everyday temperature measurements.
Kelvin (K)
The Kelvin is the SI unit of temperature. It's an absolute temperature scale where 0K represents absolute zero, the theoretical point where particles have minimal motion. Each increment in Kelvin is equal to the same increment in Celsius. Primarily used in scientific contexts.
Rankine (°R)
The Rankine scale is an absolute temperature scale based on the Fahrenheit degree. Zero on the Rankine scale is absolute zero, and a Rankine degree is the same size as a Fahrenheit degree. It's primarily used in some engineering applications in the United States.
Temperature Conversion Formulas
| From | To | Formula | Example |
|---|---|---|---|
| Celsius (°C) | Fahrenheit (°F) | °F = (°C × 9/5) + 32 | 20°C = 68°F |
| Celsius (°C) | Kelvin (K) | K = °C + 273.15 | 20°C = 293.15K |
| Celsius (°C) | Rankine (°R) | °R = (°C + 273.15) × 9/5 | 20°C = 527.67°R |
| Fahrenheit (°F) | Celsius (°C) | °C = (°F - 32) × 5/9 | 68°F = 20°C |
| Fahrenheit (°F) | Kelvin (K) | K = (°F + 459.67) × 5/9 | 68°F = 293.15K |
| Fahrenheit (°F) | Rankine (°R) | °R = °F + 459.67 | 68°F = 527.67°R |
| Kelvin (K) | Celsius (°C) | °C = K - 273.15 | 293.15K = 20°C |
| Kelvin (K) | Fahrenheit (°F) | °F = (K × 9/5) - 459.67 | 293.15K = 68°F |
| Kelvin (K) | Rankine (°R) | °R = K × 9/5 | 293.15K = 527.67°R |
| Rankine (°R) | Celsius (°C) | °C = (°R - 491.67) × 5/9 | 527.67°R = 20°C |
| Rankine (°R) | Fahrenheit (°F) | °F = °R - 459.67 | 527.67°R = 68°F |
| Rankine (°R) | Kelvin (K) | K = °R × 5/9 | 527.67°R = 293.15K |
Historical Development of Temperature Measurement
The concept of temperature measurement has evolved significantly throughout history:
- Ancient Times: Early civilizations had no standardized measurement systems and relied on subjective descriptions like "hot" and "cold."
- Early Thermoscopes (1st-2nd century CE): Primitive devices showing temperature changes without numerical scales were invented by Hero of Alexandria and others.
- Galileo Thermoscope (1592): Galileo Galilei created an early thermometer-like device that showed temperature differences.
- Fahrenheit Scale (1724): Gabriel Fahrenheit developed the mercury thermometer and the scale that bears his name.
- Celsius Scale (1742): Anders Celsius proposed a scale where 0° represented the boiling point of water and 100° the freezing point (later reversed).
- Kelvin Scale (1848): William Thomson (Lord Kelvin) developed an absolute temperature scale based on the Celsius scale.
- Modern Standards: The International System of Units (SI) adopted the Kelvin as the standard unit of temperature in 1954.
Applications of Temperature Measurement
Scientific and Industrial Applications
- Laboratory experiments and research
- Manufacturing processes and quality control
- Pharmaceutical development and storage
- Chemical reactions and material properties analysis
- HVAC systems and environmental monitoring
- Food processing and safety
Everyday Applications
- Weather forecasting and meteorology
- Cooking and baking
- Medical diagnostics and health monitoring
- Home climate control
- Automotive systems (engine temperature, etc.)
- Refrigeration and food storage