Temperature Converter
Convert between Celsius, Fahrenheit, and Kelvin instantly. Enter a temperature in any unit and see all conversions at once. Includes formulas, common references, and quick conversion links. Free and private.
Quick Conversions
Reference Table
| Description | °C | °F | K |
|---|---|---|---|
| Absolute Zero | −273.15 | −459.67 | 0 |
| Water Freezes | 0 | 32 | 273.15 |
| Room Temperature | 20 | 68 | 293.15 |
| Body Temperature | 37 | 98.6 | 310.15 |
| Water Boils | 100 | 212 | 373.15 |
| Oven (Moderate) | 180 | 356 | 453.15 |
How Temperature Conversion Works
This temperature converter handles three scales: Celsius (°C), Fahrenheit (°F), and Kelvin (K). Celsius is used worldwide for everyday temperatures, Fahrenheit is primarily used in the United States, and Kelvin is the SI unit used in science. Enter a value in any unit to see all three conversions instantly.
Temperature Conversion Formulas
°C to °F: °F = (°C × 9/5) + 32
°F to °C: °C = (°F − 32) × 5/9
°C to K: K = °C + 273.15
°F to K: K = (°F − 32) × 5/9 + 273.15
Celsius to Fahrenheit
To convert Celsius to Fahrenheit, multiply by 9/5 (or 1.8) and add 32. For example, 100°C = (100 × 1.8) + 32 = 212°F. A quick mental trick: double the Celsius value and add 30 for a rough estimate. This is accurate within a few degrees for everyday temperatures.
Fahrenheit to Celsius
To convert Fahrenheit to Celsius, subtract 32 and multiply by 5/9 (or divide by 1.8). For example, 72°F = (72 − 32) / 1.8 = 22.2°C. The crossover point where both scales read the same is −40° (−40°C = −40°F).
Kelvin Scale
The Kelvin scale starts at absolute zero (−273.15°C) — the coldest possible temperature where all molecular motion stops. It uses the same increment size as Celsius (1 K = 1°C), just offset by 273.15. Kelvin is used in physics, chemistry, astronomy, and engineering because it starts at a natural zero point.
Common Conversion Tips
Always verify the source and target units or formats before converting — selecting the wrong option is the most common mistake. For precise conversions, enter values with as many decimal places as you have available. If converting multiple items, work through them one at a time to avoid mixing up results. Bookmark this page for quick access when you need to convert again in the future.
Frequently Asked Questions
What is the formula for Celsius to Fahrenheit?
°F = (°C × 9/5) + 32. Multiply the Celsius value by 1.8 (or 9/5) and add 32. For example, 25°C = (25 × 1.8) + 32 = 77°F.
What is the formula for Fahrenheit to Celsius?
°C = (°F − 32) × 5/9. Subtract 32 from the Fahrenheit value and multiply by 0.5556 (or 5/9). For example, 72°F = (72 − 32) × 5/9 = 22.22°C.
At what temperature are Celsius and Fahrenheit equal?
Celsius and Fahrenheit are equal at −40°. This is the only point where both scales intersect: −40°C = −40°F.
What is absolute zero?
Absolute zero is 0 Kelvin (−273.15°C or −459.67°F). It is the theoretical lowest possible temperature, where all thermal motion of particles ceases. It cannot be reached in practice.
What is normal body temperature?
Normal human body temperature is approximately 37°C (98.6°F or 310.15 K). However, it can vary slightly throughout the day, typically ranging from 36.1°C to 37.2°C (97°F to 99°F).
Is my data private?
Yes. All conversions run entirely in your browser. No data is sent to any server.