How WPM and accuracy are calculated (and how to improve both)

The WPM formula

Words per minute is a normalised measure, not a count of the words on the page. One word is treated as five accepted characters, including spaces. The app divides accepted characters by five, then divides by the elapsed time in minutes. This is the standard convention used by most typing tests, and it keeps scores comparable between short and long passages.

Because the denominator is elapsed time, a pause lowers your score even if every key you pressed was correct. That is intentional. A timed paper measures sustained output, not the best burst you can produce.

What accuracy counts

Accuracy is accepted characters divided by accepted characters plus errors. A wrong key counts as an error even though it does not advance the target, so the score reflects every attempt rather than only the final text. This is stricter than comparing the finished text with the source, and it is more useful for practice because it reveals hesitation and wrong-key habits.

The target proof uses three states: green for a cluster that is complete, vermilion for the cluster you are on, and red for a cluster with a recorded miss. A pending cluster is still in ink. The colour is a guide to where to look next, not a substitute for reading the text.

Why accuracy is the better first goal

Every error costs two things: the keystroke that was wrong and the correction that follows. If you type 40 WPM at 85% accuracy, a large share of your output is unusable in an exam. If you type 28 WPM at 98% accuracy, almost all of it counts. Improving accuracy from 85% to 95% usually raises the usable score more than adding five raw WPM.

The practical rule is simple: if accuracy drops below 95%, slow down by about ten percent until it recovers. If accuracy stays above 98% for three sessions in a row, allow the speed to rise slightly. This keeps the practice loop honest.

A practice loop that works

Start with a two-minute warm-up on keys you already know. Then do one focused drill on a weak character or cluster. Then type a short real passage, and finish with the score card. Record the weakest character and the WPM. Do not change more than one variable per session.

Over a week, the numbers should move in a sawtooth pattern: a small dip when you add a new key, then recovery to a higher plateau. A straight line upward is not realistic. A flat line over two weeks usually means the practice content is too easy or too repetitive.

• Warm-up: known keys, two minutes, no pressure.
• Focus drill: the character that caused misses last time.
• Application: a real word or passage that uses it.
• Review: one score card, one note, stop.

What not to optimise

Do not optimise the score card itself. Restarting a paper to get a better number, or typing a passage you have memorised, produces a score that will not transfer to the exam. Do not chase a personal best every session either; most sessions should be practice, not a test.

Keep the keyboard visible while you are learning a new row, then hide it. Looking at the keys is not a moral failure, but it becomes a ceiling. The goal is to type from the text in front of you, not from the keyboard below it.