Temperature Converter | Konvertera.nu

Common mistakes in temperature conversion

The Celsius-to-Fahrenheit formula is °F = °C × 9/5 + 32, and the classic mistake is forgetting the +32. The multiplication alone turns 20°C into 36, but the correct answer is 68°F. Going the other way, reverse the order: subtract 32 first, then multiply by 5/9.
The +32 offset applies to temperature levels, not to temperature differences. A change of 10°C equals a change of 18°F, just the 9/5 factor, no offset. Adding 32 to a difference makes every change 32 degrees too big.
A common mistake is rounding the Celsius-to-kelvin offset to 273. It is exactly 273.15 degrees, so 25 °C is 298.15 K and absolute zero at −273.15 °C is 0 K. Kelvin also takes no degree sign, so write 'K', not '°K'.
Fahrenheit usually shows a bigger number than Celsius, but not always: the scales cross at −40°, where −40°C equals −40°F exactly. Below that point Fahrenheit reads lower than Celsius. The crossing point makes a handy sanity check for extreme cold.

Quick conversion quiz

Score: 0

7.7 degree fahrenheit equals 260 kelvin.

Correct answer: 7.7 degree fahrenheit = 260 kelvin.

24 degree celsius equals 149 kelvin.

Correct answer: 24 degree celsius = 297 kelvin.

10.2 kelvin equals -508 degree fahrenheit.

Correct answer: 10.2 kelvin = -441 degree fahrenheit.

Definitions

kelvin (K)

The SI base unit of thermodynamic temperature.

The kelvin (symbol: K) is the base unit of temperature in the International System of Units (SI). It is an absolute temperature scale where 0 K represents absolute zero. Since 2019, the kelvin is defined by fixing the numerical value of the Boltzmann constant.

degree Celsius (°C)

Metric scale based on water's freezing/boiling points.

The degree Celsius (°C) is a unit of temperature on the Celsius scale. It was originally defined by the freezing point (0 °C) and boiling point (100 °C) of water at standard pressure. It is now defined relative to the kelvin, where 0 °C corresponds to 273.15 K.

degree Fahrenheit (°F)

Scale used primarily in the United States.

The degree Fahrenheit (°F) is a unit of temperature on the Fahrenheit scale. Water freezes at 32 °F and boils at 212 °F at standard pressure. It is the official temperature scale in the United States.

degree Rankine (°R)

Absolute scale using Fahrenheit degrees.

The Rankine scale (°R) is an absolute scale of thermodynamic temperature, similar to Kelvin but using the Fahrenheit degree as its unit increment. 0 °R is absolute zero, which corresponds to -459.67 °F.

Frequently asked questions

How do I convert Celsius to Fahrenheit?

Use: °F = (°C × 9/5) + 32. Example: 20°C = 68°F.

How do I convert Fahrenheit to Celsius?

Use: °C = (°F − 32) × 5/9. Example: 68°F = 20°C.

What is the relationship between Celsius and Kelvin?

Kelvin is an absolute scale: K = °C + 273.15. Example: 0°C = 273.15 K.

What temperature is the same in Celsius and Fahrenheit?

-40 is where the scales meet: -40°C equals exactly -40°F.

How much is 1 degree Celsius in Fahrenheit?

A change of 1°C equals a change of 1.8°F. (This is for temperature differences, not converting the temperature itself.)

What is absolute zero?

Absolute zero is 0 K, which equals −273.15°C and −459.67°F.

How do I use the temperature converter on konvertera.nu?

Enter a temperature, select the unit you have, select the unit you want, and the result appears instantly.

Unit	Value	Actions
kelvin K
degree Celsius °C

Unit	Value	Actions
degree Fahrenheit °F
degree Rankine °R

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