Formula for Calculating Typing Speed
For calculating Typing Speed there are two formulas are used. One formula is based upon characters counting and the second one is directly applied on words count. Let explore the two typing test speed calculation formulas in detail.
1. Character based Formula :
A . Gross WPM

Here WPM = Word Per Minute
All typed entries = Total Key Strokes (or key depression)
Gross WPM is really the typing speed that you typed in one minute its getting by total key Stroke (Key depression) divided by 5 (One word = 5 character) and then divided by total minute to get word per minute speed.
If you type 200 character/keystroke in 1 minute then your typing speed will be = 200 / 5 = 40 WPM
But GWPM is not your actual speed, actual speed is calculating by correct word you typed known as 'Net WPM'.
Note: delete, backspace, shift and other modifier keys are not calculated in key stroke. Space between two word's also counted as 1 keystroke.
B. Net WPM Formula

Calculation of Net WPM
Net speed can be calculated by deducting errors in gross wpm. For example if you typed 40 Word in 1 Minute but you typed 3 word wrong then your Net WPM = 40 - 3 = 37 WPM
C. Accuracy Formula:
Accuracy is a percentage ratio of Gross and Net Word Speed:
Accuracy = (Net WPM / Gross WPM ) * 100 = 37 / 40 * 100 = 92.5 %
2. Words based formula :
In word base calculation each space separate two words. The word count regardless of how many characters in it. For Example the sentence "We are learning typing." As you can see here total 4 words.
A. Gross WPM : Total Words Typed / Total Time Taken (in minutes)
Example : Suppose a candidate A Typed total 350 Words in 10 Minutes:
Gross Speed in WPM : 350/10 = 35 WPM
B. Net Speed : (Total Words Typed - Word Error ) / Total Time Taken (in minutes)
Example : Suppose the A candidate typed total 350 words in 10 Minutes in which he typed 20 words wrong:
Net Speed in WPM = (350 -20) / 10 = 33 WPM
C. Accuracy : (Net WPM/ Gross WPM ) * 100
Accuracy = 33/35 * 100 = 94.28 %
Calculation of Errors
Errors are calculated by following two criteria
1. Errors which are corrected
If you correct wrong word that you typed then you will use backspace to delete that word will not calculated in WPM.
2. Errors which are incorrect
If you not correct the errors you made then you will penalized 5 character for each word error (Regardless of how many character in this wrong word). So always try to type accurate and if mistake made then correct it.