Morse Code Timing Calculator
Dit, dah and gap lengths in milliseconds for any Morse code speed, the speed from a dit length, and Farnsworth spacing for learning.
Result
Dit (one unit): 60 ms
Timings follow the PARIS standard. Keyers with weighting, or software on the CODEX standard, send slightly different lengths.
- Character speed (WPM)
- 20
- Dah (three units)
- 180 ms
- Gap inside a letter
- 60 ms
- Gap between letters
- 180 ms
- Gap between words
- 420 ms
- Time to send PARIS and its word gap
- 3 s
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How to use the Morse Code Timing Calculator
- Choose whether you know the speed in words per minute or the length of a dit.
- Enter the character speed, or the dit length in milliseconds.
- For Farnsworth timing, enter a slower overall speed; leave it empty for standard timing.
- Read the dit, dah and gap lengths in milliseconds.
How it is calculated
unit (dit) = 60 s ÷ (50 × WPM) = 1,200 ms ÷ WPMWPM from a dit = 60 s ÷ (50 × dit)dah = 3 unitsgap in a letter = 1 unitgap, letters = 3 unitsgap, words = 7 unitsFarnsworth, character speed c and overall speed sadded time t = 60 ÷ s − 31 units at speed cletter gap = 3t ÷ 19word gap = 7t ÷ 19The ratios are International Morse code as the ITU defines it in Recommendation M.1677-1. The 50 units and the 31 of them that are marks and gaps inside letters are counted from the word PARIS itself using those ratios, and the Farnsworth split is the ARRL Morse transmission timing standard (Jon Bloom, KE3Z, QEX, April 1990).
Using the numbers
For an Arduino or microcontroller keyer, the dit length is the only number the code needs: every other element is a whole multiple of it. With Farnsworth spacing the letter and word gaps are no longer multiples of the dit, so use the two gap lengths shown. At equal character and overall speeds the Farnsworth figures reduce to the standard 3 and 7 units.
With your numbers
- Dit = 60 s ÷ (50 units × 18 WPM) = 66.7 ms
- Dah = 3 dits = 200 ms; word gap = 3,659.6 ms
- Dit = 66.7 ms
Quick reference
Timings follow the PARIS standard. Keyers with weighting, or software on the CODEX standard, send slightly different lengths.
| Example | Result |
|---|---|
| 5 WPM | Dit (one unit): 240 ms |
| 13 WPM | Dit (one unit): 92.3 ms |
| 20 WPM | Dit (one unit): 60 ms |
| 25 WPM | Dit (one unit): 48 ms |
| 5 WPM Farnsworth with 18 WPM letters | Dit (one unit): 66.7 ms |
| 10 WPM Farnsworth with 18 WPM letters | Dit (one unit): 66.7 ms |
| 100 ms dit | Character speed (WPM): 12 |
| 48 ms dit | Character speed (WPM): 25 |
Where the numbers come from
The fixed figures this calculator relies on, and the published source each one was checked against. How the calculators are built and checked
4 sources
Recommendation ITU-R M.1677-1 (10/2009), International Morse code, Part I, 2.1: "A dash is equal to three dots." https://www.itu.int/rec/R-REC-M.1677-1-200910-I/
Used for
- Length of a Morse dash in dots.
Recommendation ITU-R M.1677-1 (10/2009), Part I, 2.2: "The space between the signals forming the same letter is equal to one dot." https://www.itu.int/rec/R-REC-M.1677-1-200910-I/
Used for
- Space between the dots and dashes of one Morse letter, in dots.
Recommendation ITU-R M.1677-1 (10/2009), Part I, 2.3: "The space between two letters is equal to three dots." https://www.itu.int/rec/R-REC-M.1677-1-200910-I/
Used for
- Space between two Morse letters, in dots.
Recommendation ITU-R M.1677-1 (10/2009), Part I, 2.4: "The space between two words is equal to seven dots." https://www.itu.int/rec/R-REC-M.1677-1-200910-I/
Used for
- Space between two Morse words, in dots.
Common questions about the Morse Code Timing Calculator
- How long is a dit at 20 words per minute?
- 60 milliseconds. Speed is measured on the word PARIS, which is 50 units long with its word gap, so 20 words a minute is 1,000 units a minute and one unit, a dit, is 60 ms. A dah is 180 ms, the gap between letters 180 ms and the gap between words 420 ms.
- Where does 1,200 ÷ WPM come from?
- One unit is 60 seconds divided by 50 units a word times the words per minute, which is 1.2 seconds ÷ WPM, or 1,200 ms ÷ WPM. The 50 units come from the International Morse code ratios in ITU-R M.1677-1: a dash is three dots, the gap inside a letter one dot, between letters three and between words seven. Spelled out, PARIS is 31 units of marks and in-letter gaps, 12 units of gaps between its five letters and 7 units of word gap.
- What is Farnsworth timing?
- Letters are sent at a faster character speed while the gaps between letters and words are stretched to bring the overall speed down, so learners hear each letter as a rhythm instead of counting dots. ARRL's standard, published in QEX in 1990, sends letters at 18 WPM below 18 WPM overall and splits the added time between letter and word gaps in the ratio 3 to 7.
- Why does my keyer or app give slightly different timings?
- Some software measures speed on the word CODEX, which is 60 units, and some keyers add weighting that lengthens marks and shortens gaps. This page uses PARIS with no weighting, the convention ARRL uses for code practice and tests.