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Letter Frequency Calculator

Work out letter frequency instantly with clear inputs, formula shown and shareable results.

About Letter Frequency Calculator

Spaces and punctuation are stripped, every letter is tallied, and the chosen letter's count is divided by the total letter count to give its frequency. Letter frequency is the key to breaking simple substitution codes, and in English E usually tops the list at around 12% of all letters.

Formula

Frequency

frequency % = occurrences of the letter / total letters x 100

Worked example

With the default values below, Letter Frequency Calculator returns Times that letter appears of 4. Change any input above and every figure here is recalculated in your browser.

Inputs used

Text
the quick brown fox jumps over the lazy dog
Letter to count
o

Results

Times that letter appears
4
Letters in the text
35
Share of all letters
11.43%
Most frequent letter
O (4 times)

Step by step

  1. 1Values used
  2. 2Frequency
  3. 3Times that letter appears= 4
  4. 4Letters in the text= 35
  5. 5Share of all letters= 11.43
  6. 6Most frequent letter= O (4 times)

Assumptions and limits

  • The result is derived only from the 2 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 2 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 Letter Frequency figure worked out?

frequency % = occurrences of the letter / total letters x 100. Spaces and punctuation are stripped, every letter is tallied, and the chosen letter's count is divided by the total letter count to give its frequency.

Why does this matter?

Letter frequency is the key to breaking simple substitution codes, and in English E usually tops the list at around 12% of all letters.

What do I need to enter?

Enter text, letter to count. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.

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