Celsius to Fahrenheit Converter Online

How do I convert Celsius to Fahrenheit?

Multiply by 9/5 then add 32: °F = (°C × 9/5) + 32. For example, 100°C = (100 × 1.8) + 32 = 212°F. The reverse Fahrenheit to Celsius conversion is: °C = (°F − 32) × 5/9.

What is 37 degrees Celsius in Fahrenheit?

37°C = 98.6°F. This is normal human body temperature. Using the formula: (37 × 9/5) + 32 = 66.6 + 32 = 98.6°F. A temperature of 37.5°C (99.5°F) or above is generally considered a low-grade fever in adults; 38°C (100.4°F) is the clinical threshold for fever.

What is 100 degrees Fahrenheit in Celsius?

100°F = 37.78°C. Using the formula: (100 − 32) × 5/9 = 68 × 0.5556 = 37.78°C. This is just above normal body temperature — a reading of 100°F (37.8°C) is considered a low-grade fever.

What is 180 degrees Celsius in Fahrenheit?

180°C = 356°F. Using the formula: (180 × 9/5) + 32 = 324 + 32 = 356°F. 180°C is a common baking temperature for cakes, cookies, and roasting vegetables. Other key oven conversions: 160°C = 320°F (slow/fan), 200°C = 392°F (hot), 220°C = 428°F (very hot).

What is 0 degrees Fahrenheit in Celsius?

0°F = −17.78°C. Using the formula: (0 − 32) × 5/9 = −32 × 0.5556 = −17.78°C. This is well below the freezing point of water (0°C / 32°F) and represents a very cold winter day or typical home freezer temperature (around −18°C / 0°F).

How do I convert Celsius to Kelvin?

Add 273.15: K = °C + 273.15. For example, 0°C = 273.15 K and 100°C = 373.15 K. Kelvin uses the same degree size as Celsius — it just starts at absolute zero instead of the freezing point of water.

What is absolute zero?

Absolute zero is the lowest possible temperature — 0 K, −273.15°C, or −459.67°F. At absolute zero, particles have the minimum possible thermal motion. It is theoretically unreachable but has been approached to within a billionth of a degree in laboratory conditions.

What is the difference between Kelvin and Rankine?

Both Kelvin and Rankine start at absolute zero, but they use different degree sizes. Kelvin uses Celsius-sized degrees (1 K = 1°C change), while Rankine uses Fahrenheit-sized degrees (1°R = 1°F change). The conversion is: K = °R × 5/9, or °R = K × 9/5. Rankine is used in some US engineering and thermodynamics contexts.

What temperature is the same in Celsius and Fahrenheit?

−40° is identical in both Celsius and Fahrenheit. This is the crossing point of the two scales — below −40°, Fahrenheit numbers are less negative (closer to zero) than Celsius; above −40°, Celsius is the smaller number. You can verify: (−40 × 9/5) + 32 = −72 + 32 = −40°F.

What is normal human body temperature in Celsius and Kelvin?

Normal body temperature is approximately 37°C, 98.6°F, 310.15 K, or 558.27°R. In practice body temperature varies by individual and measurement site — oral, axillary, and rectal readings differ by up to 0.5°C.

What is the boiling point of water at sea level?

Water boils at 100°C (212°F, 373.15 K, 671.67°R) at standard atmospheric pressure (1 atm / 101.325 kPa). At higher altitudes where air pressure is lower, water boils at a lower temperature — on top of Everest it boils at roughly 70°C (158°F).

Why does cooking use Fahrenheit in the US but Celsius elsewhere?

The US retained the Fahrenheit scale from its historical connection to British imperial units, while most other countries adopted Celsius as part of the metric system. For cooking, a useful rule of thumb: 350°F ≈ 175°C (moderate oven), 400°F ≈ 200°C (hot oven), 450°F ≈ 230°C (very hot oven).