Celsius to Fahrenheit Converter

How to Use This Calculator

1. Enter the temperature in Celsius.
2. The Fahrenheit and Kelvin equivalents are shown instantly.
3. Use negative values for temperatures below freezing.

Formula

Example

Frequently Asked Questions

• What is the formula to convert Celsius to Fahrenheit? ▼
  The exact formula is °F = (°C × 9/5) + 32, which can also be written as °F = (°C × 1.8) + 32. The factor 9/5 = 1.8 reflects that a Fahrenheit degree is 5/9 the size of a Celsius degree — the two scales have different zero points and different degree sizes. To verify the formula: at 0°C (freezing), (0 × 1.8) + 32 = 32°F; at 100°C (boiling), (100 × 1.8) + 32 = 180 + 32 = 212°F. For the reverse conversion, use °C = (°F − 32) × 5/9. A common mistake is forgetting to subtract 32 before multiplying. Quick mental estimate: double the Celsius temperature and add 30 (e.g., 20°C → 40+30 = 70°F; actual answer is 68°F, close enough for everyday use).
• At what temperature are Celsius and Fahrenheit equal? ▼
  Celsius and Fahrenheit scales are equal at exactly −40 degrees: −40°C = −40°F. You can derive this algebraically by setting °F = °C in the formula °F = (°C × 9/5) + 32, then solving: C = 1.8C + 32 → C − 1.8C = 32 → −0.8C = 32 → C = −40. This is a useful mnemonic: "negative forty, no difference." At temperatures above −40°, Fahrenheit values are always higher than Celsius; at temperatures below −40°, Fahrenheit values are less negative (closer to zero) than Celsius. For practical reference: −40°C/°F is an extreme cold weather temperature (routinely reached in Siberia, Canada, and Antarctica) and is also close to the operating limits of many standard batteries and lubricants.
• What is 37°C in Fahrenheit? ▼
  37°C equals 98.6°F — the standard human body temperature. Calculation: (37 × 9/5) + 32 = (37 × 1.8) + 32 = 66.6 + 32 = 98.6°F. This specific value was established by German physician Carl Wunderlich in 1851 based on measurements from thousands of patients. Modern research suggests that actual normal body temperature ranges from about 36.1°C to 37.2°C (97°F–99°F) and varies throughout the day (lowest in early morning, highest in late afternoon). A fever is typically defined as any temperature above 38°C (100.4°F). Other medically relevant temperatures: 36°C = 96.8°F (hypothermia threshold); 40°C = 104°F (serious fever); 41°C = 105.8°F (potentially dangerous).
• What is 72°F in Celsius? ▼
  72°F equals 22.2°C. Calculation: (72 − 32) × 5/9 = 40 × 5/9 = 200/9 ≈ 22.22°C. This temperature is widely recognized as a comfortable indoor room temperature in many climates, particularly in the US where thermostats are often set around 68–72°F (20–22°C). Other common room temperature references: 68°F = 20°C, 70°F = 21.1°C, 75°F = 23.9°C. The "standard temperature" used in chemistry and engineering is 20°C = 68°F (or sometimes 25°C = 77°F for thermodynamic tables). For HVAC and building systems, 22°C (71.6°F) is a commonly cited thermal comfort target. In summer, many buildings are cooled to 74–76°F = 23.3–24.4°C.
• What is 180°C (fan oven) in Fahrenheit? ▼
  180°C equals 356°F. Calculation: (180 × 9/5) + 32 = 324 + 32 = 356°F. This is a standard baking temperature — many cake and biscuit recipes specify 180°C. In an oven with fan/convection, 180°C fan is typically equivalent to 200°C conventional (the fan circulates hot air, cooking food faster and more evenly, so you reduce by about 20°C). Common baking temperature conversions: 160°C = 320°F; 170°C = 338°F; 180°C = 356°F; 190°C = 374°F; 200°C = 392°F; 220°C = 428°F. US recipes often use round Fahrenheit numbers: 325°F ≈ 163°C; 350°F = 177°C; 375°F = 191°C; 400°F = 204°C; 425°F = 218°C; 450°F = 232°C.

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