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Convert between Celsius, Fahrenheit, Kelvin, and Rankine instantly. See all four results at once, explore step-by-step formulas, and reference real-world temperature landmarks — all in one free tool, no login required. Perfect for students, engineers, cooks, and travelers.
Results rounded to 4 decimal places. Always verify for critical applications.
Scale spans Absolute Zero (−273.15°C) to Water Boiling Point (100°C). Landmarks are approximate positions.
| Landmark | °C | °F | K | °R |
|---|---|---|---|---|
Absolute Zero |
−273.15 | −459.67 | 0 | 0 |
Dry Ice (CO₂) |
−78.5 | −109.3 | 194.65 | 350.37 |
Water Freezes |
0 | 32 | 273.15 | 491.67 |
Room Temperature |
20–22 | 68–72 | 293–295 | 527–531 |
Human Body Temp |
37 | 98.6 | 310.15 | 558.27 |
Oven — 350°F (Baking) |
176.7 | 350 | 449.85 | 809.67 |
Water Boils (sea level) |
100 | 212 | 373.15 | 671.67 |
Surface of the Sun |
5,505 | 9,941 | 5,778 | 10,400 |
| From | To | Formula |
|---|---|---|
| °C | °F | °F = (°C × 9/5) + 32 |
| °C | K | K = °C + 273.15 |
| °C | °R | °R = (°C + 273.15) × 9/5 |
| °F | °C | °C = (°F − 32) × 5/9 |
| °F | K | K = (°F + 459.67) × 5/9 |
| °F | °R | °R = °F + 459.67 |
| K | °C | °C = K − 273.15 |
| K | °F | °F = (K × 9/5) − 459.67 |
| K | °R | °R = K × 9/5 |
| °R | °C | °C = (°R × 5/9) − 273.15 |
| °R | °F | °F = °R − 459.67 |
| °R | K | K = °R × 5/9 |
Multiply the Celsius value by 9/5 (or 1.8) then add 32: °F = (°C × 9/5) + 32. For example, 100°C = (100 × 1.8) + 32 = 212°F. To go the other way: °C = (°F − 32) × 5/9.
Kelvin and Celsius have the same degree size — a 1°C change equals a 1 K change. The only difference is the zero point. Celsius sets 0 at the freezing point of water, while Kelvin starts at absolute zero (the coldest possible temperature). To convert: K = °C + 273.15.
Rankine is an absolute temperature scale like Kelvin, but uses Fahrenheit-sized degrees instead of Celsius-sized degrees. Absolute zero is 0 °R, and water freezes at 491.67 °R. It is primarily used in US engineering disciplines — particularly thermodynamics, aerospace, and HVAC — where the Fahrenheit system is standard but an absolute scale is required.
Yes — negative values are valid in Celsius and Fahrenheit. However, Kelvin and Rankine cannot go below zero because they start at absolute zero. If you enter a value that would produce a negative Kelvin or Rankine result, the tool will display a warning instead of an invalid result.
Absolute zero is the lowest possible temperature — the point at which all molecular motion theoretically stops. In each scale: 0 K | 0 °R | −273.15°C | −459.67°F. It has never been achieved in practice, though scientists have gotten within billionths of a degree of it.
Disclaimer: QuickITTools.com and EnterPlanet LLC strive to make our tools as accurate as possible. Temperature conversions are mathematically precise per standard formulas. For safety-critical applications (medical, industrial, scientific), always verify results independently.