Results update instantly as you type.
Input Value
Input Unit
Celsius (°C)
Output Unit
Fahrenheit (°F)
20°C equals 68°F.
Runs entirely in your browser; no data leaves your device.
Temperature Conversion Calculator
Converting between Celsius, Fahrenheit, and Kelvin comes up in weather, cooking, travel, and science, and not everyone needs the same direction every time. This temperature converter handles all three scales in every direction from one tool. There is no need to remember which formula applies before you start, since the tool runs every direction of temperature conversion automatically.
For a specific pair, our dedicated Celsius to Fahrenheit, Fahrenheit to Celsius, and Kelvin converter pages go deeper. Each one has the full formula, worked examples, and a reference chart for that exact conversion. This page is the fastest way to convert any value between any two of the three scales right now.
Result
68°F
- Input20°C
- Formula used°F = °C × 9/5 + 32
How This Temperature Converter Works
Select your input scale and your target scale, enter a value, and the result updates instantly. All three scales, Celsius, Fahrenheit, and Kelvin, are available as both input and output.
No submit button or page reload is needed. The conversion runs in your browser the moment you type, using the same formulas used throughout this site's dedicated conversion pages.
Understanding Celsius, Fahrenheit, and Kelvin
Celsius is the standard scale across most of the world and the entire scientific community. Water freezes at 0°C and boils at 100°C on this scale. Fahrenheit remains the everyday scale in the United States, where the same two points sit at 32°F and 212°F.
Kelvin is the SI base unit for temperature, starting at absolute zero rather than the freezing point of any substance. A Kelvin degree is the same size as a Celsius degree, offset by exactly 273.15.
Worked Examples
These five examples show the converter handling different scale pairs, not just one fixed direction.
- 20°C converts to 68°F and 293.15 K.
- 98.6°F converts to 37°C and 310.15 K.
- 0 K converts to -273.15°C and -459.67°F.
- 100°C converts to 212°F and 373.15 K.
- 32°F converts to 0°C and 273.15 K.
Full Celsius, Fahrenheit & Kelvin Comparison Chart
The table below lines up common reference points across all three scales for quick lookup.
Celsius (°C) | Fahrenheit (°F) | Kelvin (K) | Reference Point |
|---|---|---|---|
| -273.15 | -459.67 | 0 | Absolute zero |
| 0 | 32 | 273.15 | Water freezes |
| 20 | 68 | 293.15 | Room temperature |
| 37 | 98.6 | 310.15 | Human body temperature |
| 100 | 212 | 373.15 | Water boils |
Explore Specific Temperature Conversions
For a deep dive into one exact pair, with the full formula, a mental math shortcut, and worked examples specific to that direction, these dedicated pages cover it in more depth than this general converter can:
- Celsius to Fahrenheit Converter: the exact °F = (°C × 9/5) + 32 formula, a quick mental trick, and common mistakes to avoid.
- Fahrenheit to Celsius Converter: the exact °C = (°F - 32) × 5/9 formula, its own mental math shortcut, and a full reference chart.
- Kelvin Converter: all four Celsius, Fahrenheit, and Kelvin pairings in one place, with the exact offset formulas for each.
Why These Formulas Are Accurate
The Celsius-Kelvin relationship and the definition of absolute zero follow the International System of Units maintained by the National Institute of Standards and Technology, not an approximation specific to this tool. Every formula used here matches that standard exactly.
Floating-point rounding is kept to a minimum in the underlying calculation. Results match hand-calculated values to the same precision a scientific calculator would give.
Is This Converter Safe to Use?
This converter runs entirely in your browser using client-side JavaScript. The values you enter are never transmitted to our servers or stored anywhere outside your current session.
You can confirm this yourself by disconnecting your internet connection after the page loads. The tool keeps working normally, since no network request is involved in producing a result.
Common Temperature Conversion Mistakes
These are the most frequent errors people make converting between scales, along with the fix for each.
Mistake | Why It Happens | Correct Approach |
|---|---|---|
| Mixing up which formula applies to which direction | Four different scale pairs means four different formulas | Check the specific conversion page for that exact pair before doing it by hand |
| Rounding the Kelvin offset to 273 instead of 273.15 | Feels close enough for casual use | Keep the full decimal for scientific or medical accuracy |
| Assuming Fahrenheit and Kelvin share a simple offset | Celsius and Kelvin do, so people expect the same | Fahrenheit to Kelvin always needs the full two-step formula |
| Treating a mental math shortcut as exact | Quick tricks are approximations, not formulas | Use the exact formula for anything medical, scientific, or precise |
Frequently Asked Questions (FAQ)
Frequently Asked Questions