Gross speed indicates the total number of characters you have typed divided by your time. When you mistype a word, an error is marked. Net speed is your total speed with errors calculated into the result. Errors are calculated in the following fashion: (total number of characters - number of mistyped words * error factor) / time The error factor is set to 5 by default. This means that 5 characters are reduced for each mistyped word. This setting can be changed in TypingMaster Manager program. For example if you type 100 keystrokes in one minute and you mistype 6 words, your gross speed will be 100 KPM and your net speed will be 70 KPM. If you are using Words per Minute notation, results are divided by 5, which is the standard word length in English language. In the example above, you would get gross speed of 20 WPM and net speed of 14 WPM.