Temperature Converter - Convert Celsius, Fahrenheit, Kelvin, Rankine & More Units
Input
0 °C
Result
32 °F
How It Works
Enter Temperature
Type the temperature value you want to convert
Select Units
Choose from and to temperature units
What is Temperature Converter?
What
A temperature converter is a tool that changes temperature from one unit to another. It helps you convert between Celsius, Fahrenheit, Kelvin, and other temperature scales quickly and easily.
Why
Different countries use different temperature units. Weather reports, cooking recipes, and science experiments often need temperature conversion. This tool makes it simple for everyone.
Applications
Used in weather forecasting, cooking and baking, medical thermometers, science labs, air conditioning systems, and international travel planning.
Temperature conversion is something we use every day. When you check the weather on your phone, the temperature might be in Celsius or Fahrenheit. When you cook food, recipes from different countries use different temperature units. Our free temperature converter helps you change between all these units in seconds.
The most common temperature units are Celsius and Fahrenheit. Most countries around the world use Celsius for daily temperature. The United States uses Fahrenheit. Scientists use Kelvin for their work. Our calculator supports all these units plus special ones like Rankine, Delisle, Newton, Réaumur, and Rømer.
Using this temperature calculator is very easy. Just type your temperature number, pick the unit you have, and pick the unit you want. The answer shows up right away. You can convert any temperature value between any two units. The calculator uses correct formulas to give you accurate results every time.
Understanding Different Temperature Scales
There are many temperature scales in the world. Each scale has its own way of measuring temperature. Some scales are very old. Some are new. People use different scales for different purposes. Let us learn about the main temperature scales.
The three most popular temperature scales are Celsius, Fahrenheit, and Kelvin. Celsius is used in most countries. Fahrenheit is used in the United States. Kelvin is used by scientists. Each scale has special points like freezing and boiling of water.
Celsius (°C)
Celsius is the most widely used temperature scale in the world. Water freezes at 0°C and boils at 100°C. Most countries use Celsius for weather reports and daily temperature measurements. It was created by Anders Celsius in 1742. The scale is easy to understand and use.
Celsius temperature is part of the metric system. Schools teach Celsius to students. Doctors use Celsius to measure body temperature in most countries. The scale makes sense because water freezing and boiling are at round numbers.
Common uses: Weather, cooking, science experiments
Fahrenheit (°F)
Fahrenheit is mainly used in the United States. Water freezes at 32°F and boils at 212°F. This scale was invented by Daniel Gabriel Fahrenheit in 1724. Many American recipes and weather reports use Fahrenheit temperatures. Americans grow up learning this scale.
The Fahrenheit scale has smaller degrees than Celsius. This means more precise temperature readings. Body temperature is 98.6°F in this scale. Many older people in America prefer Fahrenheit because they know it well.
Common uses: US weather, American recipes, medical thermometers
Kelvin (K)
Kelvin is the scientific temperature scale. It starts at absolute zero, the coldest possible temperature. Scientists use Kelvin for physics and chemistry calculations. Zero Kelvin equals -273.15°C or -459.67°F. There are no negative numbers in Kelvin.
Kelvin is named after Lord Kelvin, a famous scientist. The scale is important for scientific research. Space temperature is measured in Kelvin. Chemical reactions use Kelvin temperatures. It is the standard for science worldwide.
Common uses: Scientific research, physics, chemistry
Rankine (°R)
Rankine is like Kelvin but uses Fahrenheit-sized degrees. It starts at absolute zero like Kelvin. Engineers in the United States sometimes use Rankine for thermodynamics calculations. It was named after William Rankine. The scale combines features of Kelvin and Fahrenheit.
Rankine is not very common today. Some engineering textbooks still mention it. Power plant engineers might use this scale. It helps when working with both absolute temperature and Fahrenheit units.
Common uses: Engineering, thermodynamics, US scientific work
How to Use Temperature Converter - Simple Steps
Easy Steps to Convert Temperature
- Type the temperature number in the value box
- Select the unit you are starting from in the From dropdown
- Choose the unit you want to convert to in the To dropdown
- See your result appear instantly below
- Check the conversion table for more temperature values
Tips for Best Results
- Make sure you type the correct temperature number
- Check that you picked the right starting unit
- You can use negative temperatures for cold weather
- Try the example problems to learn more
- Use the table to see many conversions at once
Common Examples - Temperature Conversions
Celsius to Fahrenheit
0°C = 32°F - Water freezes at this temperature
20°C = 68°F - Normal room temperature
37°C = 98.6°F - Human body temperature
100°C = 212°F - Water boils at this temperature
Fahrenheit to Celsius
32°F = 0°C - Freezing point of water
68°F = 20°C - Comfortable room temperature
98.6°F = 37°C - Normal body temperature
212°F = 100°C - Boiling point of water
Celsius to Kelvin
-273.15°C = 0 K - Absolute zero temperature
0°C = 273.15 K - Water freezing point
25°C = 298.15 K - Room temperature
100°C = 373.15 K - Water boiling point
Temperature Conversion Formulas with Examples
Celsius Conversions
°C to °F: °F = °C × 9/5 + 32
Example: 25°C = 25 × 9/5 + 32 = 77°F
°C to K: K = °C + 273.15
Example: 25°C = 25 + 273.15 = 298.15 K
Fahrenheit Conversions
°F to °C: °C = (°F - 32) × 5/9
Example: 77°F = (77 - 32) × 5/9 = 25°C
°F to K: K = (°F - 32) × 5/9 + 273.15
Example: 77°F = (77 - 32) × 5/9 + 273.15 = 298.15 K
Kelvin Conversions
K to °C: °C = K - 273.15
Example: 298.15 K = 298.15 - 273.15 = 25°C
K to °F: °F = (K - 273.15) × 9/5 + 32
Example: 298.15 K = (298.15 - 273.15) × 9/5 + 32 = 77°F
Temperature Conversion Table - Quick Reference
| °C | °F | K | °R | Description |
|---|---|---|---|---|
| -273.15 | -459.7 | 0.0 | 0.0 | Absolute zero - coldest possible |
| -40 | -40.0 | 233.1 | 419.7 | Below freezing point |
| -18 | -0.4 | 255.1 | 459.3 | Below freezing point |
| 0 | 32.0 | 273.1 | 491.7 | Water freezes |
| 10 | 50.0 | 283.1 | 509.7 | Cool temperature |
| 20 | 68.0 | 293.1 | 527.7 | Cool temperature |
| 25 | 77.0 | 298.1 | 536.7 | Warm temperature |
| 30 | 86.0 | 303.1 | 545.7 | Warm temperature |
| 37 | 98.6 | 310.1 | 558.3 | Normal body temperature |
| 50 | 122.0 | 323.1 | 581.7 | Hot temperature |
| 75 | 167.0 | 348.1 | 626.7 | Hot temperature |
| 100 | 212.0 | 373.1 | 671.7 | Water boils |
| 150 | 302.0 | 423.1 | 761.7 | Hot temperature |
| 200 | 392.0 | 473.1 | 851.7 | Hot temperature |
| 300 | 572.0 | 573.1 | 1031.7 | Hot temperature |
*All values calculated at standard atmospheric pressure
Temperature Comparison Chart
-40°C
0°C
20°C
37°C
50°C
100°C
Practice Problems with Solutions
Problem 1: Celsius to Fahrenheit
Convert 25°C to Fahrenheit
Solution: 25 × 9/5 + 32 = 77°F
Problem 2: Fahrenheit to Celsius
Convert 98.6°F to Celsius
Solution: (98.6 - 32) × 5/9 = 37°C
Problem 3: Kelvin to Celsius
Convert 300 K to Celsius
Solution: 300 - 273.15 = 26.85°C
Problem 4: Celsius to Kelvin
Convert 0°C to Kelvin
Solution: 0 + 273.15 = 273.15 K
Problem 5: Negative Temperature
Convert -40°C to Fahrenheit
Solution: -40 × 9/5 + 32 = -40°F
Problem 6: Boiling Point
Convert 212°F to Celsius
Solution: (212 - 32) × 5/9 = 100°C
Real Life Uses of Temperature Conversion
🌦️ Weather Reports
Weather apps show temperature in different units. People traveling to other countries need to convert temperature to understand the weather forecast.
🍳 Cooking and Baking
Recipes from different countries use different temperature units. You need to convert oven temperature to cook food properly and safely.
🩺 Medical Use
Thermometers show body temperature in Celsius or Fahrenheit. Doctors and nurses convert temperature to check if someone has a fever.
❄️ Air Conditioning
AC and heating systems use different temperature units. You need to set the right temperature to keep your home comfortable.
🔬 Science Labs
Scientists do experiments that need exact temperature. They convert between Celsius, Kelvin, and Fahrenheit for accurate results.
🏭 Industry Work
Factories and industries monitor temperature for making products. Workers convert temperature units to follow safety rules and quality standards.
Interesting Temperature Facts You Should Know
Absolute Zero
The coldest possible temperature is -273.15°C or -459.67°F. This is called absolute zero. At this temperature, all atoms stop moving. Scientists have never reached true absolute zero in labs.
Body Temperature
Normal human body temperature is 37°C or 98.6°F. This temperature can change a little during the day. When you have a fever, your body temperature goes above 38°C or 100.4°F.
Room Temperature
Comfortable room temperature is between 20-22°C or 68-72°F. Most people feel good at this temperature. This range also saves energy when you use heating or cooling in your home.
Water Properties
Water freezes at 0°C or 32°F. Water boils at 100°C or 212°F at sea level. These temperatures change when you go to high mountains because air pressure is different there.
Cooking Temperatures
Different foods need different cooking temperatures. Chicken must reach 74°C or 165°F to be safe to eat. Beef can be eaten at 63°C or 145°F for medium-rare cooking.
Weather Extremes
The hottest temperature ever recorded on Earth was 54.4°C or 129.9°F in Death Valley, USA. The coldest was -89.2°C or -128.6°F in Antarctica. These are extreme weather records.
Frequently Asked Questions
How do I convert Celsius to Fahrenheit?
To convert Celsius to Fahrenheit, multiply the Celsius number by 9/5 and then add 32. For example: 25°C × 9/5 + 32 = 77°F. You can also use our free temperature converter tool for quick results.
What is the difference between Celsius and Kelvin?
Celsius and Kelvin have the same degree size. The difference is where they start. Kelvin starts at absolute zero which is -273.15°C. To convert Celsius to Kelvin, just add 273.15 to the Celsius temperature.
Why do some countries use Fahrenheit instead of Celsius?
The United States and a few other countries use Fahrenheit because they started using it before the metric system became popular. Most countries in the world now use Celsius as part of the metric system.
What temperature scale do scientists use?
Scientists usually use Kelvin for their work because it starts at absolute zero. This makes math calculations easier and more accurate. Celsius is also common in science work outside of physics.
How accurate is this temperature converter?
Our temperature converter uses correct math formulas and gives results accurate to 8 decimal places. The calculations follow official temperature conversion standards used all over the world.
Can I convert negative temperatures?
Yes, you can convert negative temperatures in Celsius and Fahrenheit. Kelvin and Rankine do not have negative numbers because they start at absolute zero. Negative temperatures are common in cold weather.
What is the formula to convert Fahrenheit to Celsius?
To convert Fahrenheit to Celsius, subtract 32 from the Fahrenheit number and then multiply by 5/9. For example: (77°F - 32) × 5/9 = 25°C. This formula always gives the correct answer.
Is this temperature converter free to use?
Yes, our temperature converter is completely free. You can use it as many times as you want. No registration or payment is needed. Just enter your temperature and get instant results.
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Dr. Jane Doe
VerifiedExpert Reviewer & Mathematician
Last Updated: May 19, 2026