# Video: Converting between Celsius and Kelvin

What is 27℃ in Kelvin?

04:21

### Video Transcript

What is 27 degrees Celsius in Kelvin?

In order to answer this question, we first need to know the relationship between degrees Celsius and Kelvin. So let’s draw these two number lines to represent both, degrees Celsius and Kelvin. The top orange one can be the Celsius scale and the bottom one, the pink one, can be Kelvin. As an aside, by the way, it’s important to remember that it’s not degrees Kelvin. For Celsius and Fahrenheit, we use degrees Celsius and degrees Fahrenheit. But for Kelvin, it’s just Kelvin.

Now, both of these scales have to start somewhere, specifically the lowest temperature theoretically attainable by any object in the universe. That’s probably a good place to start. So let’s label it on these scales. This temperature, of course, is known as absolute zero. And nothing can go below this temperature, no object in the universe. In degrees Celsius, absolute zero is negative 273 degrees Celsius. A bit of a random number to remember, but it’s a lot easier in Kelvin. Happily for us, absolute zero in Kelvin is zero Kelvin.

So we’ve labelled absolute zero on both of these temperature scales. Which means we can also label the zero point of the Celsius scale. Let’s say that this point is zero degrees Celsius. Now this temperature is not inherently linked to the fundamental properties of the universe, quite like absolute zero is, but come on, it’s zero degrees Celsius. We may as well label it. So what is zero degrees Celsius in Kelvin? Well, the important thing to know is that the Celsius scale and the Kelvin Scale are basically identical. The only thing that differs is where their zero points are. In other words, if you increase the temperature of any object by one degree Celsius, that’s the same as increasing it by one Kelvin.

So as we go from negative 273 Kelvin [Celsius], negative 272, negative 271, and so on and so forth, we reach zero degrees Celsius. We go up in exactly the same increments, going from zero Kelvin, one Kelvin, two Kelvin, and so on and so forth until we get to 273 Kelvin. Like we said earlier, these temperature scales are exactly the same apart from where their zero points are. Which means that on this diagram, we can then label 27 degrees Celsius, very roughly roundabout there. And we can also label that same temperature in Kelvin. And logically, this temperature must be 273 plus 27 because if 27 degrees Celsius is 27 larger than zero degrees Celsius, then this value must be 27 larger than 273 Kelvin. And this ends up being 300 Kelvin.

And so our final answer is that 27 degrees Celsius is 300 Kelvin.

Now, there are a few memory techniques that you can use to remember the conversion between degrees Celsius and Kelvin. And we’ve seen one of them already, the number line method which we’ve just used. However, there are a couple of others. For example, if you’re a visual learner, then remember this picture. The K which represents Kelvin is much larger than degrees Celsius. What this serves to tell you is that for the same temperature, the value in Kelvin, the number, is much larger than the number in degrees Celsius. So in this case, we’ve got 300 Kelvin. And that’s the same temperature as 27 degrees Celsius. But the number 300 in Kelvin is much larger than the number in degrees Celsius, which is 27. Therefore, Kelvin is larger than degrees Celsius. And this is true for any temperature. For example, 28 degrees Celsius would be 301 Kelvin. And 301 is larger than 28, and so on and so forth. You can even imagine the big nasty K having teeth trying to eat up the degree Celsius, poor little degree Celsius.

Finally, there’s one more way to remember the relationship between Kelvin and degrees Celsius. It’s a little rhyme and goes as follows: K is equal to degrees C plus 273. In other words, the value in Kelvin is equal to the value in degrees Celsius plus 273. It’s easy to remember because it rhymes, degrees C plus 273. And it’s really useful because it’s got the value of 273 in it.

So those are the ways of remembering the relationship between Kelvin and degrees Celsius. And, once again, the final answer to our question is that 27 degrees Celsius in Kelvin is 300 Kelvin.