Free Temperature Converter - Celsius, Fahrenheit, Kelvin Online Calculator
75 uses-
Conversion Result
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Celsius °C
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Fahrenheit °F
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Kelvin K
Common Temperature Reference Table
| Scenario | Celsius °C | Fahrenheit °F | Kelvin K |
|---|---|---|---|
| Absolute Zero | -273.15 | -459.67 | 0 |
| Water Freezing | 0 | 32 | 273.15 |
| Room Temperature | 25 | 77 | 298.15 |
| Normal Body Temp | 37 | 98.6 | 310.15 |
| Fever Threshold | 38 | 100.4 | 311.15 |
| High Fever | 39 | 102.2 | 312.15 |
| Water Boiling | 100 | 212 | 373.15 |
| Oven Low | 150 | 302 | 423.15 |
| Oven Medium | 180 | 356 | 453.15 |
| Oven High | 220 | 428 | 493.15 |
Temperature Conversion Tips
Core Formula
°F = °C × 9/5 + 32, and °C = (°F - 32) × 5/9. Remember 32 and 1.8 — these two numbers are all you need.
Baking Temps
Common US oven temps: 350°F = 177°C, 375°F = 190°C, 400°F = 204°C, 450°F = 232°C. Essential for American recipes.
Body Temperature
Normal body temp is 98.6°F (37°C). A fever starts at 100.4°F (38°C). These are crucial numbers for health monitoring.
Quick Mental Math
Quick F→C estimate: subtract 30, divide by 2. Example: 80°F → (80-30)/2 = 25°C (actual: 26.7°C). Good enough for daily use!
Equal Point
-40° is the same in both Celsius and Fahrenheit — the only point where the two scales meet. A fun fact to remember!
Kelvin Scale
Kelvin starts at absolute zero (-273.15°C). K = °C + 273.15. Used in science and physics. Room temperature ≈ 298K.
Frequently Asked Questions
At what temperature are Celsius and Fahrenheit the same?
-40 degrees is identical in both scales: -40°C = -40°F. This is the only intersection point of the two temperature scales.
What is absolute zero?
Absolute zero is 0 Kelvin = -273.15°C = -459.67°F. It is the theoretical lowest possible temperature where molecular motion stops.
Why does the US use Fahrenheit?
The US adopted Fahrenheit before metric became widespread. Fahrenheit was invented in 1724 and was standard in English-speaking countries before most switched to Celsius.
How do I convert Celsius oven temperatures to Fahrenheit for foreign recipes?
When following international recipes, you'll often encounter oven temperatures in Celsius. To quickly convert these to Fahrenheit for your oven, simply input the Celsius value into our converter. For instance, a common European baking temperature like 180°C converts to 356°F. This ensures your bakes turn out perfectly, preventing over or undercooking due to incorrect temperature settings.
Why does a 1-degree change in Celsius feel more significant than in Fahrenheit?
A one-degree Celsius change represents a larger temperature interval than a one-degree Fahrenheit change. This is because there are 100 degrees between the freezing and boiling points of water in Celsius (0-100°C), while there are 180 degrees in Fahrenheit (32-212°F). Consequently, each Celsius degree is 1.8 times larger than a Fahrenheit degree, making Celsius changes seem more impactful. Our converter helps you grasp these differences precisely.
What's the ideal room temperature in Celsius for pet reptiles when their care sheet is in Fahrenheit?
Reptile care sheets often list ideal temperatures in Fahrenheit. To accurately maintain your pet's environment using a Celsius thermometer, simply use our converter. For example, if a common ideal basking spot is 90°F, our tool shows this is 32.2°C. Ensure precise conversion for your reptile's health and comfort, avoiding guesswork.
How much colder is 0 degrees Fahrenheit compared to 0 degrees Celsius?
Zero degrees Fahrenheit (0°F) is significantly colder than zero degrees Celsius (0°C). While 0°C is the freezing point of water, 0°F is a much colder -17.78°C. This means when your weather app shows 0°F, you're looking at severe freezing temperatures, far below what 0°C indicates. Use our converter to instantly grasp these differences.
How do I convert between Celsius, Fahrenheit, and Kelvin using this tool?
It's super simple. Just select the temperature scale you're starting with (Celsius, Fahrenheit, or Kelvin) and enter your value in the corresponding input box. Our converter will automatically display the equivalent temperatures in the other two scales. For instance, if you type 25°C, you'll instantly see it's 77°F and 298.15K. This tool makes checking temperatures for any situation a breeze.
Can I use this converter for scientific lab measurements?
Absolutely. Scientists often need to switch between Kelvin and Celsius for experiments. Our tool handles that cleanly. For example, if your data shows 310K (human body temperature), you'll see it's 37°C and 98.6°F instantly. No rounding errors if you copy the full decimal values. Just remember that Kelvin has no negative numbers — absolute zero stops at 0K.
Is there a quick way to estimate Fahrenheit from Celsius without a calculator?
Double the Celsius number and add 30. For 20°C, that gives 70°F — pretty close to the real 68°F. This trick works best between 10°C and 30°C. For precise cooking or science, always use our converter to avoid off results.
How to Use the Temperature Converter
- Select the source unit (Celsius, Fahrenheit, or Kelvin) from the input dropdown.
- Enter the temperature value you want to convert.
- The converter instantly shows results in the target unit and all three main scales.
- Click the swap arrow to reverse the conversion direction.
- Results are calculated with high precision for scientific accuracy.
- Bookmark this page for quick access when cooking, traveling, or studying.