in this video we're going to talk about temperature conversions how to convert from units such as fahrenheit to celsius and to kelvin and vice versa so let's start with the basics let's say we have a temperature of 100 degrees celsius how can we convert that temperature into fahrenheit if you want to convert celsius to fahrenheit here's the formula that you could use the fahrenheit temperature let's just call that f so the fahrenheit temperature is 1.8 times the celsius temperature plus 32. so all you need to do is plug in the celsius temperature into the equation and you'll get the answer so it's going to be 1.8 times 100 plus 32 1.8 times 100 is 180 and 180 plus 32 18 plus 3 is 21 0 plus 2 is 2. so 180 plus 32 is 212. so 100 degrees celsius is equal to a temperature of 212 degrees on the fahrenheit scale this is the boiling point of water the water boils at 100 degrees celsius but in fahrenheit it's 212. so let's try another example of converting a temperature in celsius to fahrenheit so let's say that we want to convert 40 degrees celsius to fahrenheit go ahead and try it so we're going to use the same formula f is equal to 1.8 c plus 32. so we're going to replace c with 40. so 1.8 times 40. let's use the calculator for that so that's going to be 72. for some reason i put 3.2 instead of 32. so let's make that correction 72 plus 32 is 104. so a temperature of 104 degrees fahrenheit is equal to a celsius temperature of 40 degrees so now you know how to convert celsius to fahrenheit but let's talk about how we can convert fahrenheit to celsius so let's say we have a temperature of 98 degrees fahrenheit how can we convert that into a celsius temperature so the formula that we're going to use is going to be as follows the celsius temperature is equal to the fahrenheit temperature minus 32 divided by 1.8 so in this case it's going to be 98 minus 32 divided by 1.8 98 minus 32 we're going to subtract first that's equal to 66 next we're going to divide 66 by 1.8 and that'll give us a temperature of 36.6 repeating which you can round that to 36.7 so the celsius temperature is 36.7 degrees here's another example let's say we have a temperature of 130 degrees fahrenheit so that's the temperature in a desert on a hot day what is that in celsius feel free to take a minute and try that example so using the same formula it's the fahrenheit temperature -32 divided by 1.8 so let's replace f with 130 next let's subtract 130 by 32 so that'll give us 98 and then let's divide 98 by 1.8 so the celsius temperature is 54.4 repeating so 130 degrees fahrenheit is equal to 54.4 on the celsius scale now let's talk about another unit of temperature that is the kelvin unit if you're taking chemistry or physics typically you'll be seeing this unit you'll be using this unit a lot actually let's say we want to convert 25 degrees celsius into kelvin this is a common temperature conversion how can we do that the kelvin temperature is equal to the celsius temperature plus 273.15 now typically we tend to ignore the point 15 so we're going to use 273. so all we need to do is replace c with 25 so it's 25 plus 273 so it's 298 kelvin thus 25 degrees on a celsius scale is equal to 298 on the kelvin scale so that's how you can convert from celsius to kelvin all you need to do is just add 273 to the celsius temperature now let's say we have a temperature of 500 kelvin and we wish to convert that to the temperature in celsius what do we need to do well since the kelvin temperature is equal to the celsius plus 273 the celsius temperature is the kelvin temperature minus 273 so it's going to be 500 kelvin minus 273 and so that's 220 degrees celsius so that's how you can convert kelvin into celsius simply subtract the kelvin temperature by 273 to get the celsius temperature now let's talk about a challenge problem let's say we have the temperature in fahrenheit it's 300 degrees fahrenheit how can we convert it to kelvin feel free to pause the video and try this example problem in order to do this it's best to convert from fahrenheit to celsius and then from celsius to kelvin so we know the celsius temperature is the fahrenheit temperature minus 32 divided by 1.8 so that's going to be 300 minus 32 over 1.8 300 minus 32 is 268 and 268 divided by 1.8 is 148.8 repeating so let's round that to 0.9 thus 300 degrees fahrenheit is 148.9 degrees celsius now that we have the celsius temperature we can get the kelvin temperature so that's going to be the celsius plus 273. so it's 148.9 plus 273 and if you want to you could use the 273.15 since we have a decimal value here and the answer is going to be 422.05 kelvin so you may need to use discretion on when to add the point 15. if your celsius temperature is rounded to the nearest tenth then it may be wise to do that if it's rounded to nearest whole number then you could just add 273 to it for the sake of practice let's try another example so let's try a temperature value that's negative go ahead and convert negative 40 degrees fahrenheit to kelvin take a minute and work on that example so the celsius temperature we're going to follow the same process let's convert fahrenheit to celsius first the celsius temperature is going to be the fahrenheit temperature minus 32 over 1.8 so f is negative 40 and negative 40 minus 32 that's negative 72 negative 72 divided by 1.8 is negative 40. so this is the one temperature in which the fahrenheit temperature is the same as the celsius temperature i've actually seen that in test problems so just keep that in mind now that we have the celsius temperature we can get the kelvin temperature using this formula so since this is rounded to the nearest whole number we're going to use 273 instead of 273.15 so it's negative 40 plus 273 which is the same as 273 minus 40. and thus the kelvin temperature is 233 degrees so that's how you can convert from fahrenheit to kelvin this by converting fahrenheit to celsius first and then from celsius you can convert that to kelvin now let's try a similar problem backwards instead of going from fahrenheit to kelvin let's convert from kelvin to fahrenheit so if we have a temperature of 400 kelvin what is that in fahrenheit go ahead and pause the video and try this example what we're going to do is go from kelvin to celsius and then celsius to fahrenheit so the celsius temperature is the kelvin temperature minus 273 so we have 400 minus 273 400 minus 200 is 200 and then 200 minus 73. let's do mental math this is 200 minus 70 minus 3. 200 minus 70 is 130 and 130 minus 3 is 127. so that is the temperature in celsius so 400 kelvin is equal to 127 degrees celsius now from celsius let's go to fahrenheit the fahrenheit temperature is 1.8 times the celsius temperature plus 32. so that's going to be 1.8 times 127 plus 32. so i'm going to use the calculator for that 1.8 times 127. that is i type that in wrong 1.8 times 127 is 228.6 and then if we add 32 to that it's going to give us a fahrenheit temperature of 260 degrees so that's how we can convert from kelvin to fahrenheit you want to convert from kelvin to celsius first and then from celsius to fahrenheit