The formula
Words per minute is not measured in words. It is measured in characters, then converted using a fixed convention: one word equals five characters, spaces included. So the calculation is characters ÷ 5, divided by the elapsed time in minutes.
The five-character rule exists so that a text full of long words and a text full of short ones score the same. Without it, "I am" and "extraordinary" would both be one word, and scores would depend on the passage rather than on you.
Gross versus net
Gross WPM counts every character you produced. Net WPM subtracts the damage: mistakes reduce the character count, which is why a fast run with a bad error rate can lose to a slower clean one.
This calculator asks for an error count so it can show both. If you do not know your error count, leave it at zero and read the gross figure — just remember it overstates speed the way a stopwatch overstates a lap run.
Where people go wrong
- Counting only letters. Spaces count, and in English they are roughly one in six characters.
- Dividing by seconds. WPM is per minute, so a 30-second run doubles if you forget to convert.
- Using real words instead of characters, which makes short-word passages look fast.
- Comparing a gross number from one site with a net number from another. They are not the same measurement.
Skip the arithmetic
If you would rather not count characters at all, the typing test counts them for you, along with errors, consistency and per-second speed.