Temperature Converter
Convert between Celsius, Fahrenheit, and Kelvin. Unlike most units, temperature scales have different zero points, so a conversion shifts by an offset as well as scaling.
Formula: multiply the source value by 33.8
Quick Conversions
About this tool
Temperature scales are affine, not simple ratios. Values pass through Kelvin, then to the target scale.
How to use it
Pick the starting scale, type a temperature, then choose the target scale. Negative values are valid for Celsius and Fahrenheit.
K = C + 273.15
C = (F â 32) Ă 5/9
F = C Ă 9/5 + 32
Examples
100 °C to °F
100 à 9/5 + 32 = 212 °F.
20 °C to °F
Using °F = °C à 9/5 + 32: 20 °C = 68 °F.
300 K to °C
Using °C = K â 273.15: 300 K = 26.85 °C.
Reference temperatures on each scale
| Reference point | °C | °F | K |
|---|---|---|---|
| Absolute zero | -273.15 | -459.67 | 0 |
| Water freezes | 0 | 32 | 273.15 |
| Room temperature (approx.) | 20 | 68 | 293.15 |
| Typical body temperature | 37 | 98.6 | 310.15 |
| Water boils at sea level | 100 | 212 | 373.15 |
FAQ
Can Kelvin be negative?
Physically no. The converter still lets you type values so you can inspect the math.
Why not multiply by a single factor?
Celsius and Fahrenheit do not share a zero. An offset is required.
Is the conversion exact?
Yes. The scale definitions (0 °C = 273.15 K, and one Fahrenheit degree is 5/9 of a kelvin) are exact. Results are only rounded for display.
Why can't I multiply by a single factor?
Because 0 °C, 0 °F, and 0 K are three different temperatures. Converting needs an offset as well as a scale, so the page shows the formula instead of a factor.