Temperature Converter
Convert any temperature unit to another with this free temperature converter. It supports 4 units including celsius, fahrenheit, kelvin, rankine. Pick a conversion below for a dedicated calculator, formula, and reference table. For example, 1 °C = 33.8 °F.
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About these units
Celsius (°C)
- Definition
- The degree Celsius (°C) is a metric temperature unit where water freezes at 0° and boils at 100° at standard pressure.
- History
- Proposed by Swedish astronomer Anders Celsius in 1742 (originally inverted), the scale was later flipped to its modern form.
- Current use
- Celsius is the everyday temperature scale across most of the world for weather, cooking, and medicine.
Fahrenheit (°F)
- Definition
- The degree Fahrenheit (°F) is a temperature unit where water freezes at 32° and boils at 212° at standard pressure.
- History
- Introduced by physicist Daniel Gabriel Fahrenheit in 1724 using brine and body temperature as reference points.
- Current use
- Fahrenheit remains the common temperature scale in the United States and a few other territories.
Kelvin (K)
- Definition
- The kelvin (K) is the SI base unit of temperature, starting at absolute zero with the same degree size as Celsius.
- History
- Proposed by William Thomson (Lord Kelvin) in 1848 and redefined in 2019 by fixing the Boltzmann constant.
- Current use
- Kelvin is used throughout science and engineering, especially in physics, chemistry, and astronomy.
Rankine (°R)
- Definition
- The degree Rankine (°R) is an absolute temperature scale that uses Fahrenheit-sized degrees starting at absolute zero.
- History
- Proposed by Scottish engineer William Rankine in 1859 as the absolute counterpart to Fahrenheit.
- Current use
- Rankine appears in some US engineering and thermodynamics work, particularly in aerospace.
Frequently asked questions
What temperature units can I convert?
This temperature converter supports 4 units: celsius, fahrenheit, kelvin, rankine. Select any pair below to open a dedicated converter with a formula and conversion table.
How accurate is the temperature converter?
Conversions use exact definitional factors, so results are accurate to the precision you need for science, engineering, and everyday use. Values are rounded only for display.
Is the temperature converter free?
Yes. Every temperature conversion is completely free, needs no sign-up, and runs entirely in your browser — your inputs never leave your device.
Free, private, and instant — every conversion runs in your browser.
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