Temperature Converter

What this temperature converter does

This temperature converter helps you convert between Celsius, Fahrenheit, Kelvin, Rankine, Réaumur, Delisle, Newton, and Rømer in one clean tool. You can use it as a Celsius to Fahrenheit converter, Fahrenheit to Celsius converter, Celsius to Kelvin converter, Fahrenheit to Kelvin converter, oven temperature converter, body temperature converter, weather temperature converter, or general temperature conversion calculator.

The tool is designed for everyday use and practical accuracy. It can help when you are reading a recipe from another country, checking weather in a different temperature scale, converting a body temperature reading, studying science, comparing appliance settings, or working with technical measurements. Unlike length, volume, or weight conversion, temperature conversion needs formulas because each scale can start from a different zero point.

If you are working with other measurements too, visit the Measurement and Conversion Tools hub. You may also need the Length and Distance Converter, Weight and Mass Converter, Volume and Capacity Converter, or Area Converter.

How temperature conversion is different from other unit conversions

Most measurement converters use a simple factor. For example, a length converter can convert meters to centimeters by multiplying by 100. A weight converter can convert kilograms to grams by multiplying by 1000. Temperature is different because temperature scales do not all share the same zero point.

For example, 0°C equals 32°F, not 0°F. This means Celsius to Fahrenheit needs both multiplication and addition. The same idea applies to Kelvin and Rankine because they are absolute temperature scales. Kelvin starts at absolute zero, while Celsius is offset by 273.15 degrees from Kelvin.

This is why a reliable temperature converter should use formulas instead of simple base factors. If you also need factor-based measurement tools, the Speed Converter, Digital Storage Converter, and Height Converter can help with related tasks.

Celsius, Fahrenheit, and Kelvin explained

Celsius is widely used around the world for weather, cooking, science education, home settings, and general daily life. In Celsius, water freezes at 0°C and boils at 100°C under standard atmospheric pressure. That makes it easy to remember common reference points for everyday use.

Fahrenheit is commonly used in the United States for weather, oven settings, body temperature, and home thermostats. In Fahrenheit, water freezes at 32°F and boils at 212°F under standard conditions. A room temperature that might be described as 20°C to 22°C is roughly 68°F to 72°F.

Kelvin is mainly used in science and engineering. It is an absolute temperature scale, which means 0 K represents absolute zero. Kelvin degrees are the same size as Celsius degrees, but Kelvin starts 273.15 degrees lower. That means 0°C equals 273.15 K, and 100°C equals 373.15 K.

How to convert Celsius to Fahrenheit

To convert Celsius to Fahrenheit, multiply the Celsius value by 9 divided by 5, then add 32. The formula is F = (C × 9 / 5) + 32. This formula works because Fahrenheit degrees are smaller than Celsius degrees and the Fahrenheit scale is offset by 32 degrees at the freezing point of water.

For example, 25°C becomes 77°F. First, multiply 25 by 9 divided by 5, which gives 45. Then add 32, which gives 77. This is a useful conversion for weather, air conditioning, indoor comfort, and travel.

If you are planning around dates and travel, the Time Zone Converter, Travel Time Calculator, and Jet Lag Calculator may also be helpful.

How to convert Fahrenheit to Celsius

To convert Fahrenheit to Celsius, subtract 32 from the Fahrenheit value, then multiply by 5 divided by 9. The formula is C = (F - 32) × 5 / 9. This is one of the most useful conversions for people comparing US weather or recipes with metric references.

For example, 98.6°F converts to 37°C. First, subtract 32 from 98.6, which gives 66.6. Then multiply by 5 divided by 9, which gives 37. This is why 98.6°F is often listed as the familiar Celsius equivalent of normal body temperature.

For household planning, you might also use the Household and Utility Tools, Electricity Bill Calculator, and Electricity Cost Per Appliance Calculator.

How to convert Celsius to Kelvin and Kelvin to Celsius

Kelvin and Celsius have the same degree size, so the conversion is simpler than Fahrenheit. To convert Celsius to Kelvin, add 273.15. The formula is K = C + 273.15. To convert Kelvin to Celsius, subtract 273.15. The formula is C = K - 273.15.

For example, 0°C equals 273.15 K. A value of 100°C equals 373.15 K. A value of 0 K equals -273.15°C. Since Kelvin begins at absolute zero, Kelvin values cannot go below 0 K in physically valid temperature conversion.

This converter checks for impossible Kelvin and Rankine inputs below zero. It also warns if a conversion would create a physically impossible absolute-scale result. That makes it safer for science, school, engineering, and technical references.

Rankine and Réaumur explained

Rankine is an absolute temperature scale related to Fahrenheit. Like Kelvin, it starts at absolute zero, but each Rankine degree is the same size as a Fahrenheit degree. The formula from Celsius to Rankine is R = (C + 273.15) × 9 / 5. The formula from Rankine to Celsius is C = (R - 491.67) × 5 / 9.

Réaumur is a historical temperature scale where water freezes at 0°Ré and boils at 80°Ré under standard conditions. The formula from Celsius to Réaumur is Ré = C × 4 / 5. The formula from Réaumur to Celsius is C = Ré × 5 / 4.

The converter also includes Delisle, Newton, and Rømer for advanced or historical reference. Most people will use Celsius, Fahrenheit, and Kelvin most often, but these additional scales make the tool more complete for school, research, and curiosity-driven conversions.

Common temperature conversion table

Practical examples for weather, cooking, body temperature, science, and travel

For weather, temperature conversion helps when forecasts use a scale you do not normally use. A traveler from a Celsius-using country may need to understand a forecast of 86°F, which is 30°C. A traveler from the United States may need to understand 10°C, which is 50°F.

For cooking, oven temperatures often need conversion between Celsius and Fahrenheit. A recipe that says 180°C is about 356°F, usually rounded to 350°F in many oven guides. A recipe that says 400°F is about 204.4°C, often rounded to 200°C or 205°C depending on the oven and recipe style.

For body temperature, 98.6°F equals 37°C. But context matters. Body temperature can vary by person, time of day, age, activity, measurement method, and health condition. This converter can handle the math, but it does not diagnose health conditions.

For science, Kelvin is important because it begins at absolute zero. If you are working with school assignments, lab values, physics formulas, or chemistry problems, Kelvin may be the correct scale to use. Always follow the formula or unit requirement in your class or technical reference.

For travel planning, temperature is only one part of the trip. You may also find the Travel and Lifestyle Tools, Trip Budget Calculator, Fuel Cost Calculator, and Packing List Generator useful.

Body temperature conversions and why context matters

Body temperature is one of the most common reasons people convert Fahrenheit to Celsius or Celsius to Fahrenheit. A common reference is 98.6°F, which equals 37°C. A reading of 100.4°F equals 38°C, which is often used as a fever reference in many health contexts.

Still, body temperature should not be judged by conversion alone. Oral, ear, forehead, rectal, and underarm measurements can differ. Time of day, recent activity, hydration, medication, and age can also affect readings. Use this converter for the number conversion, then follow medical or professional guidance for interpretation.

If you are tracking daily routines, the Date Difference Calculator, Countdown and Days Until Calculator, and Pomodoro Timer can help with planning and reminders.

Oven and cooking temperature conversions

Oven temperature conversions are useful because many recipes are written for a specific region. A US recipe may use Fahrenheit, while a European or Australian recipe may use Celsius. This can matter for cakes, bread, roasted vegetables, meat, cookies, and casseroles.

Common oven conversions include 160°C to 320°F, 180°C to 356°F, 200°C to 392°F, and 220°C to 428°F. In real kitchens, these are often rounded to nearby oven settings like 325°F, 350°F, 400°F, or 425°F. If your oven uses fan or convection settings, the recipe may recommend a lower temperature than a conventional oven.

For cooking measurements beyond temperature, try the Cooking Converter, Volume and Capacity Converter, and Weight and Mass Converter.

Freezing, boiling, and room temperature reference points

Reference points make temperature conversions easier to understand. Water freezes at 0°C or 32°F. Water boils at 100°C or 212°F under standard atmospheric pressure. A comfortable room temperature is often around 20°C to 22°C, which is about 68°F to 71.6°F.

These reference points help you quickly estimate the meaning of a converted temperature. If a forecast says 32°F, think freezing. If a forecast says 86°F, think about 30°C and warm weather. If a recipe says 180°C, think about a moderate oven around 350°F.

For household comfort and utility planning, you may also use the Water Bill Calculator, Gas and Fuel Consumption Calculator, Internet and Data Usage Calculator, and Laundry Cost Calculator.

Mistakes to avoid when converting temperatures

One common mistake is treating temperature conversion like length or weight conversion. Celsius to Fahrenheit is not a simple multiplication by one factor because the two scales have different zero points. You must multiply and adjust by 32.

Another mistake is mixing up a temperature value and a temperature change. A temperature of 1°C equals 33.8°F, but a change of 1°C equals a change of 1.8°F. This matters in science, heating, cooling, weather analysis, and appliance performance.

A third mistake is using Kelvin like Celsius. A Kelvin value should not use a degree symbol in formal scientific writing, and it cannot go below zero. If you enter a negative Kelvin or Rankine value, this converter will warn you instead of showing an impossible result.

Finally, avoid rounding too early. If you are doing a school problem or technical calculation, keep more decimals during the calculation and round only at the end. For everyday cooking and weather, practical rounded values are usually enough.