Words per minute
Work out a typing speed — and see why the answer depends on what you typed rather than how many words it was. Nothing you type here leaves your browser. It is worked out on your own device, so there is nothing to send and nothing to log — which matters more for text than for most things, because people paste in work they are not supposed to paste anywhere.
A word is five characters, and always has been
Words per minute does not count words. It counts characters and divides by five, and that five is an assumption about the average length of an English word — including spaces and punctuation.
Arif and Stuerzlinger set the metric out as
WPM = (|T| − 1) ÷ S × 60 × ⅕
and say the fifth “accounts for the average length of a word in characters including spaces, numbers, and other printable characters”. They cite Yamada's 1980 historical study of typewriters for it, so the figure predates every typing test on the web by decades.
So your score depends on what you typed
Two passages of exactly nineteen characters score exactly the same,
whether they are ten words or two. Type
a b c d e f g h i j and you have written ten words;
type extraordinarily abc and you have written two. The
test gives both the same number.
That is not a flaw — it is what makes scores comparable between people, tests and languages. But it does mean a test built from short common words flatters you, and one full of long words does not, and neither is measuring how many words you can write in a minute.
The minus one is not a typo
The time is measured from the first key press to the last. That times the gaps between keystrokes, and there is always one fewer gap than there are characters — typing a single character takes no time at all by this definition.
Most calculators leave it out. Over a minute of typing it moves the answer by a fraction of a word; over a five-second burst it is several per cent. Both numbers are shown above so you can see the size of it.
Net against gross
Gross words per minute ignores mistakes. Net docks one word for each uncorrected error, spread over the same time. A test that quotes a single figure is almost always quoting gross, which is the flattering one.
Reading speed is a different measurement
Reading speed is usually quoted in real words, not five-character units, so the two figures are not comparable even though they share a name. A reading speed and a typing speed of “200 wpm” are measuring different things.