Reading Level (Flesch Kincaid) Calculator

Work out reading level (flesch kincaid) instantly with clear inputs, formula shown and shareable results.

About Reading Level (Flesch Kincaid) Calculator

Flesch-Kincaid grade level is 0.39 x average sentence length plus 11.8 x average syllables per word minus 15.59, and reading ease uses the same two averages on a 0-100 scale. Both formulas rest on only two levers, sentence length and word length, so shortening sentences is usually the quickest way to bring a passage down a grade.

Formulas

Grade level

FKGL = 0.39 x (words / sentences) + 11.8 x (syllables / words) - 15.59

Reading ease

FRE = 206.835 - 1.015 x (words / sentences) - 84.6 x (syllables / words)

Worked example

With the default values below, Reading Level (Flesch Kincaid) Calculator returns Flesch-Kincaid grade level of 7.96. Change any input above and every figure here is recalculated in your browser.

Inputs used

Total wordsminimum 1: 120
Total sentencesminimum 1: 8
Total syllablesminimum 1: 180

Results

Flesch-Kincaid grade level: 7.96
Flesch Reading Ease (0-100): 64.7
Average sentence length: 15.00 words
Average syllables per word: 1.500

Step by step

1Values used
2Grade level
3Reading ease
4Flesch-Kincaid grade level= 7.96
5Flesch Reading Ease (0-100)= 64.7
6Average sentence length= 15.00 words
7Average syllables per word= 1.500

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is the Reading Level (Flesch Kincaid) figure worked out?

FKGL = 0.39 x (words / sentences) + 11.8 x (syllables / words) - 15.59. Flesch-Kincaid grade level is 0.39 x average sentence length plus 11.8 x average syllables per word minus 15.59, and reading ease uses the same two averages on a 0-100 scale.

Why does this matter?

Both formulas rest on only two levers, sentence length and word length, so shortening sentences is usually the quickest way to bring a passage down a grade.

What do I need to enter?

Enter total words, total sentences, total syllables. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.