Temperature Converter
Convert between Celsius, Fahrenheit, Kelvin, Rankine, Delisle, Reaumur and Romer. Results update instantly. Last updated: June 2026.
Best for: Converting Celsius to Fahrenheit for a recipe written abroad, and checking Kelvin values for a science assignment
Limitations: Converts temperature points rather than temperature differences, which matters in some engineering calculations
Best suited for: Home cooks following overseas recipes and students checking science homework
Popular Temperature Conversions
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Temperature Conversion Formulas
Reference Temperatures
| Condition | °C | °F | K |
|---|---|---|---|
| Water boils | 100 | 212 | 373.15 |
| Body temperature | 37 | 98.6 | 310.15 |
| Room temperature | 22 | 71.6 | 295.15 |
| Water freezes | 0 | 32 | 273.15 |
| Absolute zero | -273.15 | -459.67 | 0 |
Frequently Asked Questions
How do I convert Celsius to Fahrenheit?
Multiply by 9/5 (which is 1.8) and then add 32. Formula: °F = (°C × 1.8) + 32. Example: 25°C = (25 × 1.8) + 32 = 45 + 32 = 77°F. A rough mental estimate: double the Celsius value and add 30.
What is 37 degrees Celsius in Fahrenheit?
37°C = 98.6°F, which is normal human body temperature. Formula: (37 × 1.8) + 32 = 66.6 + 32 = 98.6°F.
What is absolute zero?
Absolute zero is the theoretical minimum temperature: -273.15°C, -459.67°F, and 0 Kelvin. At absolute zero, particles have the minimum possible thermal motion. It is physically impossible to reach exactly absolute zero, though scientists have come extremely close in laboratory conditions.
How do I convert Fahrenheit to Kelvin?
Convert to Celsius first using °C = (°F - 32) × 5/9, then add 273.15 to get Kelvin. Example: 212°F to Kelvin: (212 - 32) × 5/9 = 100°C + 273.15 = 373.15 K.
At what temperature are Celsius and Fahrenheit the same?
Celsius and Fahrenheit are equal at -40 degrees. -40°C = -40°F. This is the only point where both scales give the same numerical value. You can verify this: (-40 × 1.8) + 32 = -72 + 32 = -40.
How Does the Temperature Converter Work?
Temperature is the one conversion on this site that is not a simple multiplication, because the scales have different zero points as well as different degree sizes. Celsius to Fahrenheit multiplies by 9/5 and then adds 32; the addition is what makes it an offset conversion rather than a ratio. Kelvin shares the Celsius degree size but starts at absolute zero, so the conversion is an addition of 273.15 with no multiplication.
The definitions behind these scales are set out in the BIPM SI Brochure.
Common Temperature Conversions and When You Need Them
Cooking is the most frequent case, since recipes move between Celsius and Fahrenheit and oven dials differ by market. A moderate oven at 180 degrees Celsius is 356 degrees Fahrenheit, usually rounded to 350 on an American dial.
Weather is the second, where the same forecast reads 30 degrees Celsius or 86 degrees Fahrenheit. Body temperature is the third and the one where precision matters: 37 degrees Celsius is 98.6 degrees Fahrenheit, and a one degree Celsius rise is nearly two degrees Fahrenheit, which is why a fever looks more dramatic on the Fahrenheit scale. Scientific and engineering work is the fourth, where kelvin is required because ratios only make sense on an absolute scale.
What Are the Standard Temperature Measurements?
The kelvin is an SI base unit, defined by fixing the Boltzmann constant. Absolute zero is 0 K, equal to minus 273.15 degrees Celsius. The Celsius scale is defined relative to the kelvin with the same degree size, so a temperature difference of one degree Celsius equals one kelvin exactly. Fahrenheit is defined against Celsius, with 32 degrees at the freezing point of water and 212 at its boiling point at standard pressure.