Convert between 8 temperature scales instantly with real-time results, validation, and educational insights. The most comprehensive temperature converter online.
Water freezes at 0°C and boils at 100°C
Water freezes at 32°F and boils at 212°F
Absolute temperature scale, 0 K = absolute zero (-273.15°C)
Absolute scale using Fahrenheit degrees, 0°R = absolute zero
Rare temperature scales used historically or in specialized applications
Higher numbers = colder
By Isaac Newton
Used in cheese making
Influenced Fahrenheit
Higher = Colder
Theoretical temperature where molecular motion stops (0 K, -273.15°C, -459.67°F)
Temperature and pressure where all three phases coexist (273.16 K for water)
Temperature above which liquid and gas phases cannot be distinguished
Rate of temperature change per unit distance (°C/m or °F/ft)
State where objects have the same temperature and no heat transfer occurs
Amount of heat required to raise temperature by one degree (J/K or cal/°C)
Unit measuring deviation from reference temperature for heating/cooling calculations
Stress caused by rapid temperature changes in materials
Study of extremely low temperatures (typically below -150°C or -238°F)
Created by Anders Celsius in 1742. Originally, 0°C was boiling point and 100°C was freezing point, but this was later reversed. Water freezes at 0°C and boils at 100°C at sea level.
Developed by Daniel Gabriel Fahrenheit in 1724. Uses 32°F as water's freezing point and 212°F as boiling point. Still commonly used in the United States.
Proposed by Lord Kelvin in 1848. An absolute temperature scale starting at absolute zero (-273.15°C), where all molecular motion stops. Used in scientific calculations.
Created by William Rankine in 1859. Like Kelvin but uses Fahrenheit-sized degrees. Absolute zero is 0°R. Used in engineering, especially thermodynamics.
Master temperature conversions with this comprehensive guide covering all scales, formulas, and real-world applications.
Temperature is a fundamental physical quantity that measures the average kinetic energy of particles in a substance. It determines the direction of heat flow between objects and is crucial for countless scientific, industrial, and everyday applications. Understanding temperature scales allows us to quantify thermal energy precisely and communicate thermal measurements universally.
Different temperature scales were developed for various practical and scientific needs:
Celsius, Fahrenheit, and historical scales that use arbitrary zero points based on physical phenomena like water freezing.
Kelvin and Rankine scales that start at absolute zero, where all molecular motion theoretically stops.
Delisle, Newton, Réaumur, and Rømer scales developed by early scientists, now mainly of historical interest.
Developed by Swedish astronomer Anders Celsius in 1742, originally with 0° representing water's boiling point and 100° representing freezing. Carl Linnaeus later reversed this scale to the modern convention we use today. The scale was officially renamed from "centigrade" to "Celsius" in 1948 to honor its creator.
Perfect for recipe conversions, food safety temperatures, and kitchen thermometer readings.
International weather reports, climate data, and meteorological measurements.
Body temperature monitoring, medical equipment calibration, and pharmaceutical storage.
Created by German physicist Daniel Gabriel Fahrenheit in 1724. Originally based on three points: the temperature of a mixture of ice, water, and salt (0°F), the freezing point of water (32°F), and human body temperature (originally 96°F, later refined to 98.6°F). The scale provides finer granularity than Celsius for everyday temperatures.
US weather services use Fahrenheit, making it familiar for 330+ million Americans.
Many US industries, HVAC systems, and cooking equipment use Fahrenheit standards.
Deeply embedded in American culture, education, and daily conversation.
Named after William Thomson, 1st Baron Kelvin, who proposed the concept of absolute temperature in 1848. The Kelvin scale is based on absolute zero (-273.15°C), the theoretical temperature where all molecular motion ceases. It's the base unit of thermodynamic temperature in the International System of Units (SI).
Quantum mechanics, particle physics, and low-temperature research require absolute temperature measurements.
Stellar temperatures, cosmic microwave background radiation, and planetary science calculations.
Cryogenics, superconductivity research, and precision manufacturing processes.
Developed by Scottish engineer and physicist William Rankine in 1859. The Rankine scale combines the absolute zero concept of Kelvin with Fahrenheit degree sizing. It's primarily used in thermodynamic calculations in countries that use the Imperial measurement system.
Heating, ventilation, and air conditioning calculations in US commercial buildings.
Steam cycle analysis and thermal efficiency calculations in American power generation.
Rocket engine performance and atmospheric modeling in US space programs.
Created by French astronomer Joseph-Nicolas Delisle in 1732. Unusually, higher Delisle values indicate colder temperatures. Water boils at 0°De and increases as temperature decreases, making it counterintuitive compared to modern scales.
°De = (100 - °C) × 3/2
Developed by Sir Isaac Newton around 1700, one of the earliest temperature scales. Newton set "melting snow" at 0°N and "heat of the human body" at 12°N. The scale defined 33°N as water's boiling point, creating a practical measurement system.
°N = °C × 33/100
Created by René Antoine Ferchault de Réaumur in 1730. Uses 80° between water's freezing and boiling points, making it useful for specific industrial applications. The scale was widely adopted in continental Europe for scientific and commercial purposes.
°Ré = °C × 4/5
Developed by Danish astronomer Ole Christensen Rømer in 1701. This scale significantly influenced Fahrenheit's later work. Rømer set brine's freezing point at 0°Rø and human body temperature at 22.5°Rø, creating the foundation for future temperature measurement.
°Rø = °C × 21/40 + 7.5
Common questions about temperature conversion and temperature scales
Use the formula: °F = (°C × 9/5) + 32. For example, 20°C = (20 × 9/5) + 32 = 68°F. Our converter does this automatically with real-time results.
Celsius uses 0°C for water freezing and 100°C for boiling. Fahrenheit uses 32°F for freezing and 212°F for boiling. Celsius is used globally, while Fahrenheit is primarily used in the US.
This is the only point where Celsius and Fahrenheit scales intersect. It's a mathematical coincidence where both formulas yield the same numerical value.
Our converter provides 6-decimal precision for scientific accuracy. It uses exact mathematical formulas without rounding errors, making it suitable for professional and research applications.
Use Kelvin for scientific calculations, gas laws, thermodynamics, and when dealing with absolute temperatures. Kelvin starts at absolute zero and is essential for physics equations.
Absolute zero (0 K, -273.15°C, -459.67°F) is the theoretical temperature where all molecular motion stops. It's impossible to reach because it would require infinite energy to remove all heat.
Rankine is used in US engineering, particularly for thermodynamic calculations, HVAC systems, and power plant efficiency calculations. It's like Kelvin but uses Fahrenheit-sized degrees.
Historical scales like Delisle, Newton, Réaumur, and Rømer are important for understanding scientific history, replicating historical experiments, and specialized applications like cheese making.
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