Words per minute, or WPM, is the amount of words typed in a minute. A word is defined as five characters, and a space counts as a character, meaning that "of it" counts as one word just like "nitro" counts as one word. WPM is calculated by dividing the total number of words by the fractional amount of minutes typed.
WPM increases as you type words, but decreases as you mistype a word. Practice is recommended so that you mistype words fewer and fewer times.
For example, let's say you type for exactly 2 minutes and type 810 characters. 810 characters divided by 5 characters per word is 161, meaning that you typed 161 words in that time period. 161 words divided by 2 minutes is 80.5, meaning that you typed 80.5 WPM.
You can also measure WPM over a shorter period of time, like 20 seconds. If you typed for 20 seconds and typed 185 characters (37 words), then you can divide 37 words by 1/3 minutes and get 111 WPM. Here is the simple formula to calculate your WPM:
(characters typed / 5) / (seconds typed / 60) = Words per Minute, or WPM.
The highest WPM anyone has ever obtained without cheating is Sean Wrona's (arenasnow12) high speed of 212 WPM. Sean is a world record typist.
Note: After reaching an average of 86 WPM or higher, Nitro Type requires you to take a one-time speed verification test to make sure you are not cheating.