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Temperature Converter

Convert temperature between Celsius, Fahrenheit, and Kelvin. Instant result in your browser, no signup, nothing saved.

Common conversions

0°C = 32°F

Calculation formula
0 × 9/5 + 32 = 32

The value in every unit

  • Celsius0°C
  • Fahrenheit32°F
  • Kelvin273.15K

This is a unit converter only. It is not a live weather forecast and not medical advice about body temperature or treating a fever. The calculation runs in your browser only; no value is sent to a server or saved.

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Quick answer: this free temperature converter changes a value between Celsius (°C), Fahrenheit (°F), and Kelvin (K), instantly and entirely in your browser. Type a number, pick the unit you are converting from and the unit you want, and the result updates as you type. You can swap the two units with one click, use the quick-conversion buttons for common reference points (water freezing and boiling, body temperature, absolute zero), and see the exact formula used to get the answer. It is a unit converter only: handy for reading a forecast from an American site, following a US baking recipe, or working through a science or lab problem. It is not a live weather forecast, and it is not medical advice about body temperature or treating a fever; for health questions, talk to a qualified clinician. Everything runs on your device. The value, the units, and the result are never saved and never sent to any server, and refreshing the page clears it all. Last updated: May 2026.

01

How to use this tool

  1. 01Enter a valueType a number in the "Value to convert" field. Decimals are allowed (for example 36.6 or 0.5), and negative values are fine for Celsius and Fahrenheit (cold weather, cryogenics). In Kelvin the value must be zero or higher, because absolute zero is the floor.
  2. 02Choose the unitsPick the unit you are converting from (default: Celsius) and the unit you want (default: Fahrenheit). Swap the two with one tap on "Swap". The result updates immediately on any change.
  3. 03Use the common conversionsSix ready-made buttons jump straight to reference points: water freezing, water boiling, average body temperature (37°C), the point where Celsius and Fahrenheit meet (−40°), absolute zero (0K), and a room-temperature value in Kelvin.
  4. 04See the formulaBelow the result, a formula line shows exactly how the answer was reached, for example "37 × 9/5 + 32 = 98.6". Useful for learning, and for showing your work instead of just a number.
  5. 05Copy the resultThe "Copy result" button copies a short summary line (for example "100°C = 212°F") that you can paste anywhere. There is no print or download button.
02

When is this useful?

  • Reading a weather forecast from abroadA US site shows the temperature in °F. Convert it to °C quickly to decide what to wear or pack. The tool is a unit converter only and does not pull live forecast data.
  • Following a US baking recipeA recipe says to set the oven to 350°F. Convert instantly: 350°F is about 176.67°C, which means roughly 175-180°C on a typical home oven dial.
  • Science homework and lab workA physics problem asks you to convert between °C and K, or to show the range from absolute zero to room temperature. The formula is shown right next to the result so you can check the steps.
  • Reading an equipment or lab specA datasheet lists an operating temperature in °F or K. Convert it to the unit you know and check whether the device fits your conditions.
  • Packing for a trip to a different climateYou check a forecast on a foreign site in °F, convert to °C, and decide what to put in your bag. No signup, no cookies.
03

Examples

  • The reference points of water0°C = 32°F (freezing). 100°C = 212°F (boiling at standard atmospheric pressure). Both values are the agreed anchors of the Celsius scale.
  • Average body temperature37°C is about 98.6°F, and 310.15K. This is a statistical average only; it is not a diagnosis and does not replace a medical check.
  • Where Celsius and Fahrenheit meet−40°C = −40°F (exactly). A fun fact: this is the single point where both scales give the same number.
  • Absolute zero0K = −273.15°C = −459.67°F. The lowest temperature that is theoretically possible. The tool rejects values below absolute zero because they have no physical meaning.
04

Tips for a better result

  • The scales are defined, not just "hot" or "cold"Celsius is anchored to the freezing and boiling points of water at standard pressure. Fahrenheit was historically defined with different anchors. Kelvin starts at absolute zero. One degree means a different step on each scale, which is why the formula needs both an offset (32 or 273.15) and a scale factor (9/5 or 5/9).
  • Oven dials: round sensiblyWhen a US recipe asks for 350°F (about 176°C), round to 175°C on a home oven. Differences of a few degrees are negligible in most recipes, so there is no need to chase the exact decimal.
  • It is not a weather forecastThe tool does not connect to any weather service. If your destination changes temperature through the day, check an official forecast site and convert the specific values you care about here.
  • Your value stays with youThe value you type stays on your device. It is not sent over the network and not saved. Your choice of source and target unit is not shared with any server either.

  • Conversion formulas

    All six directional conversions, written out exactly: • Celsius to Fahrenheit: F = C × 9/5 + 32 • Fahrenheit to Celsius: C = (F − 32) × 5/9 • Celsius to Kelvin: K = C + 273.15 • Kelvin to Celsius: C = K − 273.15 • Fahrenheit to Kelvin: K = (F − 32) × 5/9 + 273.15 • Kelvin to Fahrenheit: F = (K − 273.15) × 9/5 + 32 Celsius and Fahrenheit need both a scale factor (9/5 or 5/9) and an offset (32), because one degree is a different size on each scale. Celsius and Kelvin share the same degree size, so the conversion is just an offset of 273.15.

  • How the conversion works

    The tool does two steps: first it normalizes the input to Celsius, then it converts from Celsius to the target unit. The intermediate formulas are exact: F→C is (f−32)×5/9, C→F is c×9/5+32, C→K is c+273.15, and K→C is k−273.15. A direct Fahrenheit-to-Kelvin conversion is chained through Celsius to keep it accurate. There is no internal rounding; only the final display trims unnecessary digits so you never see floating-point noise.

  • Common reference points

    A few values worth memorizing: • Water freezes: 0°C = 32°F = 273.15K • Water boils (standard pressure): 100°C = 212°F = 373.15K • Average body temperature: 37°C ≈ 98.6°F = 310.15K • Comfortable room temperature: about 20-22°C = 68-72°F • Celsius and Fahrenheit are equal: −40°C = −40°F • Absolute zero: 0K = −273.15°C = −459.67°F A quick mental trick for Celsius to Fahrenheit: double the Celsius value and add about 30 for a rough estimate (close near room temperature).

  • Which scale is used where

    Fahrenheit is used mainly in the United States. Celsius is the everyday standard in most of the world. Kelvin is an absolute scale used in the physical sciences, astronomy, and thermal engineering. All three measure the same physical quantity, but with different unit sizes and different starting points, so the same temperature shows up as different numbers on each scale.

  • What this tool does not do

    It is not medical advice about fever or treating a high temperature, not a diagnosis, not a medication dosing guide, not a live weather forecast, and not a source of meteorological data. It also does not provide safe cooking temperatures for food (USDA and food-safety authorities are the right source for that) or safe operating limits for industrial or medical equipment. Any real-world decision that depends on a temperature value should rest on an authoritative source for that field.

  • Privacy

    Everything happens in your browser. The value you enter, the units you pick, and every input are not saved, not sent to a server, and not passed to analytics. Refreshing the page clears it all. There is no signup, no account, and no tracking of the value entered or the result.

05

Frequently asked questions

How do I convert Celsius to Fahrenheit?

Multiply the value by 9/5 and add 32. For example: 100°C × 9/5 + 32 = 212°F (the boiling point of water).

How do I convert Fahrenheit to Celsius?

Subtract 32 from the value, then multiply by 5/9. For example: (98.6 − 32) × 5/9 = 37°C (average body temperature).

How do I convert Celsius to Kelvin?

Add 273.15 to the Celsius value: K = C + 273.15. For example: 0°C = 273.15K, 25°C = 298.15K, and 100°C = 373.15K. To go back, subtract 273.15. There is no multiplication, because both scales use the same degree size.

What is 100°C in Fahrenheit?

100°C is 212°F, the boiling point of water at standard atmospheric pressure. The math: 100 × 9/5 + 32 = 212.

What is the relationship between Celsius and Kelvin?

Kelvin equals Celsius plus 273.15. For example: 0°C = 273.15K and 100°C = 373.15K. There is no multiplication, because both scales use the same degree size; only the starting point differs.

What is absolute zero?

The lowest temperature that is theoretically possible: 0K, which is −273.15°C or −459.67°F. The tool rejects values below this because they have no physical meaning.

What happens if I enter a value below absolute zero?

A short message explains the value is below absolute zero and no result is shown. In Kelvin the floor is 0, in Celsius it is −273.15, and in Fahrenheit it is −459.67.

How precise is the result, and does it round?

The math is exact with no internal rounding. Only the final display trims trailing digits so you do not see floating-point noise, showing more decimals for very small values and up to two for normal ones.

Does this give medical advice about body temperature?

No. It is a unit converter only. It will convert 38.5°C to 101.3°F with no medical context. For questions about a fever, body temperature, or treating any medical condition, talk to a qualified clinician.

Is anything uploaded or saved?

No. The whole calculation runs in your browser. The value, the units, and the result are not stored, not sent to a server, and not passed to analytics. The tool is free to use with no signup.

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