Celsius to Fahrenheit Converter
Celsius is a temperature scale where 0°C is the freezing point of water and 100°C is the boiling point. To convert Celsius to Fahrenheit, multiply by 9/5 and add 32 — so 37°C (normal body temperature) equals 98.6°F.
Convert any Celsius temperature to Fahrenheit instantly. Includes body temperature reference, fever guide, and common temperature chart.
How to Convert Celsius to Fahrenheit
To convert Celsius to Fahrenheit multiply the Celsius temperature by 1.8 and add 32. For a quick estimate double the Celsius number and add 30. Normal body temperature is 37 degrees Celsius which equals 98.6 degrees Fahrenheit. A fever begins at 38 degrees Celsius which is 100.4 degrees Fahrenheit. Water freezes at 0 degrees Celsius which is 32 degrees Fahrenheit. Water boils at 100 degrees Celsius which is 212 degrees Fahrenheit. The Celsius scale is used by most countries worldwide while Fahrenheit is used primarily in the United States, the Bahamas, and a few other countries.
Popular Temperature Conversions
Body Temperature & Fever Guide
| °C | °F | What it means |
|---|---|---|
| 35°C | 95°F | Below normal (hypothermia risk) |
| 36°C | 96.8°F | Low normal |
| 37°C | 98.6°F | Normal body temperature |
| 37.5°C | 99.5°F | Slightly elevated |
| 38°C | 100.4°F | Low-grade fever |
| 38.5°C | 101.3°F | Fever |
| 39°C | 102.2°F | Moderate fever |
| 40°C | 104°F | High fever |
| 41°C | 105.8°F | Very high fever — dangerous |
| 42°C | 107.6°F | Hyperpyrexia — medical emergency |
Temperature Reference Chart
| Celsius (°C) | Fahrenheit (°F) | Description |
|---|---|---|
| -40°C | -40°F | Where °C Equals °F |
| -30°C | -22°F | |
| -20°C | -4°F | |
| -10°C | 14°F | |
| -5°C | 23°F | |
| 0°C | 32°F | Freezing Point of Water |
| 5°C | 41°F | |
| 10°C | 50°F | |
| 15°C | 59°F | |
| 16°C | 60.8°F | |
| 18°C | 64.4°F | |
| 20°C | 68°F | Room Temperature |
| 21°C | 69.8°F | Comfortable Room Temperature |
| 22°C | 71.6°F | Ideal Room Temperature |
| 25°C | 77°F | Warm Day |
| 30°C | 86°F | Hot Day |
| 35°C | 95°F | |
| 36°C | 96.8°F | |
| 37°C | 98.6°F | Normal Body Temperature |
| 38°C | 100.4°F | Low Grade Fever |
| 39°C | 102.2°F | Moderate Fever |
| 40°C | 104°F | High Fever |
| 41°C | 105.8°F | Very High Fever — Dangerous |
| 50°C | 122°F | |
| 60°C | 140°F | |
| 70°C | 158°F | |
| 80°C | 176°F | |
| 100°C | 212°F | Boiling Point of Water |
| 150°C | 302°F | Very High Heat |
Temperature Conversion Guide
Formula: (°C × 9/5) + 32 = °F. Quick mental trick: double the Celsius value and add 30 for an approximate Fahrenheit value.
To convert Fahrenheit to Celsius: subtract 32, then multiply by 5/9.
The Celsius scale is used in most countries worldwide and in all scientific contexts. The Fahrenheit scale is primarily used in the United States.
Frequently Asked Questions
- What is 37°C in Fahrenheit?
- 37°C is 98.6°F. This is the average normal human body temperature, defined by the World Health Organization and used as the baseline on medical thermometers worldwide. The normal body temperature range is 36.1°C to 37.2°C (97°F to 99°F). A temperature above 38°C (100.4°F) is clinically considered a fever in adults. The 37°C / 98.6°F benchmark was established by German physician Carl Wunderlich in 1851 and remains the medical standard today.
- What is 38°C in Fahrenheit?
- 38°C is 100.4°F. According to the World Health Organization and most clinical guidelines, a body temperature of 38°C or above is the threshold for fever in adults. At 38.5°C (101.3°F), it is a moderate fever; at 39°C (102.2°F), a significant fever; at 40°C (104°F), a high fever that warrants medical attention. Parents are often advised to contact a doctor if a child's temperature exceeds 38°C. The 38°C / 100.4°F mark is the most important temperature reference point after normal body temperature.
- What is the formula to convert Celsius to Fahrenheit?
- The formula is: °F = (°C × 9/5) + 32. In practice: multiply the Celsius value by 1.8, then add 32. Example: 20°C × 1.8 = 36, plus 32 = 68°F. For a quick mental estimate, double the Celsius value and add 30 (this gives a result within 2–3 degrees for everyday temperatures). To convert back from Fahrenheit to Celsius: °C = (°F − 32) × 5/9. The Celsius scale was defined by Anders Celsius in 1742, anchored at 0°C (water freezes) and 100°C (water boils at sea level).
- What is 0°C in Fahrenheit?
- 0°C is 32°F. This is the freezing point of water at standard atmospheric pressure (1 atm / sea level). The 0°C anchor point is what defines the entire Celsius scale — developed by Anders Celsius in 1742. In everyday terms, 0°C is the temperature at which ice forms, roads become slippery, and water pipes are at risk of freezing. The Fahrenheit equivalent of 32°F comes from the formula: (0 × 9/5) + 32 = 32.
- What is 100°C in Fahrenheit?
- 100°C is 212°F. This is the boiling point of water at sea level (standard atmospheric pressure of 101.325 kPa). The 0–100 range of Celsius was deliberately designed around water's phase transitions — making Celsius intuitive for science, cooking, and medicine. At higher altitudes, where atmospheric pressure is lower, water boils below 100°C (for example, at 3,000 metres water boils at about 90°C). The formula gives: (100 × 9/5) + 32 = 180 + 32 = 212°F.
- When should I be concerned about a fever temperature?
- A body temperature at or above 38°C (100.4°F) is a fever. Low-grade fever is 38–38.9°C (100.4–102°F) — usually manageable with rest and fluids. A temperature of 39–39.9°C (102–103.8°F) is a moderate fever; 40°C (104°F) or above is a high fever and you should contact a doctor. In infants under 3 months, any fever above 38°C is a medical emergency. In adults, a temperature above 41°C (105.8°F) — called hyperpyrexia — requires immediate emergency care. Always use an accurate thermometer and consult a healthcare professional for medical decisions.