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Reading Fluency Calculator
Calculate oral reading fluency as words correct per minute and accuracy from the words read, the errors, and the time.
Whole words attempted, including any errors
A whole number from 0 up to the words read
Use 1 for a one-minute probe. Decimals such as 1.5 are allowed.
Optional. Divided by 60 and added to the minutes. 60 seconds equals 1 minute.
Formula
words correct per minute = (words read − errors) / minutes
accuracy = words correct / words read
Enter the words read, the errors, and a time in minutes or seconds to see words correct per minute and accuracy.
This reading fluency calculator scores an oral reading probe as words correct per minute and accuracy. Enter the words read, the errors, and the time in minutes, seconds, or both. Seconds are divided by 60 and added to the minutes, and words correct per minute equals the words read minus the errors, divided by that time. Accuracy is the words correct divided by the words read, shown as a fraction such as 85/90 for 90 words and 5 errors in 1 minute, which is 85 words correct per minute. One-minute probes are the usual timing. A time of zero, or an error count above the words read, is called out on the page. Teachers compare the words-correct-per-minute score with the grade chart their school uses.
Score an oral reading probe in words correct per minute
Enter the words read, the errors, and the time. A one-minute oral reading probe uses 1 in the minutes box. If the student reads for another length of time, add the seconds, or put the whole time in seconds and leave minutes blank. Seconds are divided by 60 and added to the minutes before the rate is calculated. The score updates as you type. Ninety words, 5 errors, and 1 minute is (90 − 5) / 1, which is 85 words correct per minute, and the accuracy is 85/90.
Words correct per minute is that reading rate: subtract the errors from the words read, then divide by the time in minutes. Accuracy is the words read correctly divided by the words read, written as that fraction and as a percentage of the words attempted. Mispronunciations, substitutions, omissions, and words supplied after a pause of about three seconds are the errors many oral reading fluency probes count, while repetitions and self-corrections are often left out, and the passage directions still decide the tally you type. Teachers compare the words-correct-per-minute score with the grade chart their school uses.
Frequently Asked Questions
How do you calculate words correct per minute?
Subtract the errors from the words read, then divide by the time in minutes. Words correct per minute = (words read − errors) / minutes. For 90 words, 5 errors, and 1 minute, that is (90 − 5) / 1 = 85 WCPM.
How is reading accuracy calculated?
Divide the words read correctly by the words read. Words correct are the words read minus the errors, so the same example has accuracy 85/90, which is 94.44% of the words attempted.
What if the probe is not exactly one minute?
Put the extra time in the seconds box, or type the full time in seconds. Seconds are divided by 60 and added to the minutes. Sixty seconds matches 1 minute, so 90 words and 5 errors in 60 seconds is still 85 WCPM. Forty-five seconds is 0.75 minutes, and the same words and errors score (90 − 5) / 0.75, which is about 113.33. The calculator rounds words correct per minute to a whole number, so it shows ≈ 113 WCPM. A time of 0 minutes has no rate, because the formula divides by the time.
How should a words-correct-per-minute score be compared with a grade?
Teachers compare the score with the oral reading fluency chart their school uses for that grade and season. The calculator returns the words correct per minute and the accuracy fraction from the numbers you enter, and the grade comparison stays with that chart.