Temperature Converter
Convert temperature between Celsius, Fahrenheit and Kelvin — with a body temperature fever guide.
Body temperature guide
Common temperature reference points
| Description | °C | °F | K |
|---|---|---|---|
| Water freezes | 0°C | 32°F | 273.15 K |
| Cold room | 16°C | 60.8°F | 289.15 K |
| Room temperature | 20–22°C | 68–72°F | 293–295 K |
| Comfortable warm | 25°C | 77°F | 298.15 K |
| Hot summer day (India) | 40°C | 104°F | 313.15 K |
| Normal body temp | 37°C | 98.6°F | 310.15 K |
| Water boils (sea level) | 100°C | 212°F | 373.15 K |
| Absolute zero | −273.15°C | −459.67°F | 0 K |
Conversion formulas
Frequently asked questions
What is normal body temperature in Celsius?
Normal adult body temperature ranges from 36.1°C to 37.2°C (97°F to 99°F). The classic "98.6°F / 37°C" is a historical average — actual normal varies by person, time of day (lower in the morning, higher in the evening), measurement site (oral, axillary, rectal), and age.
At what temperature is a fever considered dangerous?
A temperature above 39.4°C (103°F) in adults warrants medical attention. Above 40°C (104°F) is considered a high fever and requires urgent care. In children under 3 months, any fever above 38°C (100.4°F) requires immediate medical evaluation.
Why does India use Celsius while the US uses Fahrenheit?
India uses the Celsius (centigrade) scale as part of the metric system adopted officially after independence. The Fahrenheit scale is used in the United States as a legacy unit. Celsius is used by most of the world. Kelvin is used exclusively in science and engineering.
What is absolute zero?
Absolute zero is 0 Kelvin = −273.15°C = −459.67°F. It is the lowest theoretically possible temperature, at which all molecular motion stops. It has never been perfectly achieved but scientists have gotten within billionths of a degree of it in laboratory conditions.
Why does water boil at different temperatures in the mountains?
Water's boiling point depends on atmospheric pressure. At sea level (101.3 kPa), water boils at 100°C. At altitude, atmospheric pressure is lower, so water boils at lower temperatures. At 2,000 m altitude (e.g. Shimla, Ooty), water boils at about 93°C — which is why cooking takes longer at high altitude.