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Temperature converter

Convert between Celsius, Fahrenheit, and Kelvin instantly. See all conversions at once with formulas, a visual thermometer, and reference temperatures.

212 °F
Fahrenheit
373.15 K
Kelvin
100 °C
Celsius (input)
-273.15°C0°C100°C
Extreme Heat
formulas
°F = °C × 9/5 + 32
K = °C + 273.15
Reference°C°FK
Absolute Zero-273.15-459.670
Water Freezes032273.15
Room Temperature2271.6295.15
Body Temperature3798.6310.15
Water Boils100212373.15

Click any row to load that temperature

What is Temperature Converter?

A temperature converter is a tool that translates temperature values between the three major measurement scales: Celsius, Fahrenheit, and Kelvin. Celsius (°C) is used in most of the world and in science for everyday temperatures, with 0° as water's freezing point and 100° as its boiling point. Fahrenheit (°F) is primarily used in the United States, where water freezes at 32°F and boils at 212°F. Kelvin (K) is the SI unit for thermodynamic temperature used in physics and engineering, starting at absolute zero (−273.15°C) — the coldest theoretically possible temperature. This converter handles all three scales simultaneously: enter a value in any unit and instantly see the equivalent in both other scales. It shows the exact mathematical formulas used for each conversion, displays a visual thermometer bar with color-coded temperature zones, and includes reference points like body temperature, room temperature, and water phase changes. All calculations run entirely in your browser with no server interaction.

How to Use Temperature Converter

  1. 1

    Enter a temperature value

    Type any number into the temperature input field. Select the unit you are converting from — Celsius (°C), Fahrenheit (°F), or Kelvin (K) — using the unit selector buttons. The converter accepts negative numbers, decimals, and extreme values.

  2. 2

    Read the converted results

    The results section immediately displays the equivalent temperature in the other two scales. Each result shows the numeric value, unit symbol, and scale name. Use the copy button next to any result to copy it to your clipboard.

  3. 3

    Use references and the visual scale

    The temperature bar shows where your value falls on a color-coded scale from absolute zero to boiling water. Below the bar, the reference temperatures table lists common benchmarks — click any row to load that temperature into the converter.

Features

  • Converts between Celsius, Fahrenheit, and Kelvin simultaneously
  • Real-time conversion updates as you type with no delay
  • Shows the exact mathematical formula used for each conversion
  • Visual temperature bar with gradient coloring from cold to hot
  • Color-coded zone labels: Extreme Cold, Freezing, Cold, Comfortable, Warm, Hot, Extreme Heat
  • Reference temperature table with absolute zero, water freeze/boil, body temp, and room temp
  • One-click copy buttons on every converted value
  • Runs 100% in your browser — no data sent to any server

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Frequently Asked Questions

How do I convert Celsius to Fahrenheit?+
Multiply the Celsius value by 9/5 (or 1.8) and add 32. The formula is °F = °C × 9/5 + 32. For example, 100°C becomes (100 × 1.8) + 32 = 212°F. This converter applies the formula automatically and shows it in the formulas section.
What is absolute zero?+
Absolute zero is the lowest theoretically possible temperature, where all molecular motion stops. It equals 0 Kelvin, −273.15°C, or −459.67°F. No physical system can reach absolute zero exactly, though laboratories have come within billionths of a degree.
Why are there three different temperature scales?+
Celsius was designed around water phase changes (0° freeze, 100° boil) for practical use. Fahrenheit was designed for weather and daily life, with 0°F based on the coldest temperature Daniel Fahrenheit could create and 100°F close to human body temperature. Kelvin starts at absolute zero, making it essential for physics and thermodynamics where negative temperatures would be meaningless.
Is 0 Kelvin the same as 0 Celsius?+
No. 0 Kelvin (absolute zero) equals −273.15°C. Meanwhile, 0°C (water freezing point) equals 273.15 K. The Kelvin and Celsius scales have the same degree size, but their zero points differ by exactly 273.15 degrees.
What temperature is the same in Celsius and Fahrenheit?+
The two scales intersect at −40 degrees. At −40°C, the Fahrenheit value is also −40°F. You can verify this with the formula: (−40 × 9/5) + 32 = −72 + 32 = −40. This is the only point where both scales read the same number.
How accurate are the conversions?+
The converter calculates to full floating-point precision and displays results rounded to up to 4 decimal places, trimming trailing zeros for clean output. This precision is more than sufficient for scientific, engineering, cooking, and everyday use cases.