Sentence CounterFree online other calculator — instant results, no sign-up
Estimate sentences using terminal punctuation.
Sign in to save results and favorites.
About the Sentence Counter
The Sentence Counter estimates how many sentences a text contains by identifying terminal punctuation, such as periods, question marks, and exclamation marks. For the default text, "Hello world. This is a sample.", it reports 2 sentences. It is a quick punctuation-based estimate rather than a grammatical analysis.
- Text
- Enter the passage to check; this input is text with no measurement units, and the resulting count is expressed in sentences.
Formula and method
S = ∑ᵢ₌₁ⁿ eᵢ; for "Hello world. This is a sample.", S = 1 + 1 = 2 sentences.
- SThe estimated number of sentences.
- nThe number of character positions in the input text.
- iA character position in the input text.
- eᵢAn indicator equal to 1 when terminal punctuation at position i is recognized as a sentence ending, and 0 otherwise.
The calculator scans the text for terminal punctuation and totals the recognized sentence endings. In the default text, the period after "world" marks one ending, and the period after "sample" marks another. Adding those endings produces the result of 2 sentences.
Worked example
These are the calculator's starting values and the results it actually produces for them.
Inputs
- TextHello world. This is a sample.
Results
- Result2 sentences
How to use the Sentence Counter
- 1Enter or paste your passage into the Text field.
- 2To reproduce the worked example, use exactly "Hello world. This is a sample.".
- 3Run the calculation using the entered text.
- 4Read the Result row; the default text returns 2 sentences.
- 5Review abbreviations, unusual punctuation, or unfinished text if the estimate differs from your intended sentence count.
Reading your result
The Result row gives the estimated total number of sentences in the Text field. A result of 2 sentences for the default input means the calculator recognized two sentence endings; it does not indicate word count, sentence length, or grammatical correctness.
Limitations
Terminal punctuation is an imperfect proxy for sentence boundaries. Periods in abbreviations, decimal numbers, and web addresses can resemble sentence endings, while a sentence without final punctuation may be missed. Ellipses and repeated punctuation can also create ambiguity. The supplied example establishes the result for two ordinary period-terminated sentences but does not establish the exact handling of these edge cases.
Common questions
Why does the default text produce 2 sentences?+
"Hello world. This is a sample." contains two ordinary sentence-ending periods, one after "world" and one after "sample", so the estimate is 2 sentences.
Can questions and exclamations count as sentences?+
Yes. Question marks and exclamation marks are terminal punctuation, so the estimate is not limited to sentences ending with periods.
Will a line break count as a sentence ending?+
A line break is not terminal punctuation. Do not assume that placing text on separate lines will make each line count as a sentence.
Why might abbreviations or ellipses affect the result?+
Their periods can look like sentence endings to a punctuation-based counter. Check these cases manually rather than treating the result as a definitive grammatical count.
Does the calculator save my information?+
Calculations run in your browser. While signed in, inputs and results are automatically recorded in account history; saving a result creates a separate saved record.
You might also like
Word Counter
Count whitespace-separated words.
Character Counter
Count Unicode code points with and without whitespace.
Line Counter
Count logical lines, including a trailing empty line.
Text Reverser
Reverse the order of Unicode code points.
Text Palindrome Checker
Check a palindrome while ignoring punctuation and letter case.
Text Slugifier
Create a lowercase ASCII slug from text.
Results are estimates for informational purposes and are not financial, medical or legal advice.