Temperature Converter
Convert between Celsius, Fahrenheit, and Kelvin instantly, in any direction.
Introduction
Temperature is one of the most commonly converted measurements in daily life — weather forecasts, cooking instructions, medical readings, and scientific work all use different scales depending on context and location. The United States primarily uses Fahrenheit, most of the rest of the world uses Celsius, and scientific and engineering fields rely on Kelvin. The Temperature Converter handles all three scales, in any direction, with the internationally standardized formulas.
What This Tool Does
This converter takes a temperature value and two scale selections — the scale you're converting from and the scale you want to convert to — and instantly returns the equivalent temperature. It supports all six possible direction pairs between Celsius, Fahrenheit, and Kelvin, using the exact linear formulas that define the relationships between these scales.
How to Use
1. Enter the temperature value you want to convert.n2. Select the scale you're converting from (Celsius, Fahrenheit, or Kelvin).n3. Select the scale you want to convert to.n4. Click Calculate to see the converted temperature instantly.n5. Use Copy to grab the result, or Print for a physical reference.
Worked Example
Example 1 — Weather conversion: Convert 20°C to Fahrenheit.nCalculation: (20 × 9/5) + 32 = 36 + 32 = 68°F.nResult: 68°F — a comfortable room temperature in both scales.nnExample 2 — Cooking conversion: Convert 350°F (a common baking temperature) to Celsius.nCalculation: (350 − 32) × 5/9 = 318 × 5/9 = 176.67°C.nResult: 176.67°C — useful when following a recipe written in the opposite scale from your oven's dial.nnExample 3 — Scientific conversion: Convert 25°C (room temperature) to Kelvin.nCalculation: 25 + 273.15 = 298.15 K.nResult: 298.15 K — the standard way room temperature is expressed in scientific contexts.nnExample 4 — Body temperature: Convert 98.6°F (normal human body temperature) to Celsius.nCalculation: (98.6 − 32) × 5/9 = 66.6 × 5/9 = 37°C.nResult: 37°C — confirming the well-known equivalence between these two commonly cited body temperature figures.
Formula & Logic
The three scales relate to each other through fixed linear formulas:nCelsius to Fahrenheit: °F = (°C × 9/5) + 32nFahrenheit to Celsius: °C = (°F − 32) × 5/9nCelsius to Kelvin: K = °C + 273.15nKelvin to Celsius: °C = K − 273.15nFahrenheit to Kelvin: K = (°F − 32) × 5/9 + 273.15nKelvin to Fahrenheit: °F = (K − 273.15) × 9/5 + 32nnThese formulas exist because each scale defines its zero point and degree size differently. Celsius sets 0° at water's freezing point and 100° at its boiling point. Fahrenheit sets a different zero point and uses smaller degree increments (180 degrees between freezing and boiling, versus 100 for Celsius). Kelvin is an absolute scale starting at absolute zero, using the same degree size as Celsius but offset by 273.15.
Common Use Cases
Cooking and baking: Converting oven temperatures between recipes written in different scales.nWeather and travel: Understanding forecasts when traveling between countries using different temperature scales.nMedicine and healthcare: Converting body temperature readings between Fahrenheit and Celsius for accurate interpretation.nScience and engineering: Converting between Celsius and Kelvin for laboratory work, thermodynamics, and materials science.nHVAC and home climate control: Understanding thermostat settings when equipment or documentation uses a different scale.nEducation: Teaching and verifying the relationship between temperature scales in science curricula.
Tips
For quick mental estimates, remember that 0°C = 32°F and 100°C = 212°F as reliable reference points.nWhen traveling, a fast mental approximation for Celsius to Fahrenheit is to double the Celsius value and add 30 — close enough for weather-appropriate clothing decisions, though not exact.nFor scientific work, always use the precise formula (this tool) rather than rounded approximations, since small errors compound in further calculations.nBookmark this tool if you regularly cook from international recipes or work with equipment calibrated in a different scale than your default.nnExample 5 — Scientific to Fahrenheit: Convert 310 K (a temperature relevant in biology, close to human body temperature) to Fahrenheit.nCalculation: (310 − 273.15) × 9/5 + 32 = 36.85 × 9/5 + 32 = 66.33 + 32 = 98.33°F.nResult: 98.33°F — illustrating how scientific Kelvin readings translate to a familiar Fahrenheit context.
Frequently Asked Questions
Multiply the Celsius value by 9/5 (1.8), then add 32. For example, 20°C x 1.8 = 36, plus 32 = 68°F.
Subtract 32 from the Fahrenheit value, then multiply by 5/9. For example, (68 - 32) x 5/9 = 20°C.
Add 273.15 to the Celsius value. For example, 25°C + 273.15 = 298.15 K.
0°C equals 32°F — this is the freezing point of water.
100°C equals 212°F — this is the boiling point of water at sea level.
Normal human body temperature is approximately 37°C, or 98.6°F.
Kelvin is an absolute temperature scale where 0 K represents absolute zero, the theoretical point where molecular motion stops — it's treated as a unit of magnitude rather than a 'degree' relative to a reference point like freezing water.
No. Kelvin starts at absolute zero (0 K), which is the coldest physically possible temperature — there are no negative Kelvin values in classical physics.
Absolute zero (0 K) equals -273.15°C and -459.67°F.
The United States primarily uses Fahrenheit for everyday temperature (like weather forecasts), while most of the rest of the world uses Celsius. Kelvin is used almost universally in scientific contexts.
Yes — the conversion formulas used are the standard, internationally recognized formulas for Celsius, Fahrenheit, and Kelvin, accurate to two decimal places.
Last updated: August 7, 2026