Use the free tool above, then read on for how it works, a worked example, and practical tips.
What this tool does
Every Morse transmission is built from strict timing, and knowing how long a message takes helps you plan a call, a beacon slot, or a practice session. This calculator turns a speed in words per minute and a message into dit and dah lengths and the total time the message takes on the air.
How it works
The tool uses the standard rule that a dit lasts 1200 divided by the speed in words per minute, in milliseconds, with a dah three times as long. Gaps count too: one unit between elements of a letter, three units between letters, and seven units between words, so the total is the sum of every element and gap in your message.
How to use it
- Enter your values in the boxes above.
- Press the calculate or play button.
- Read the result shown below the tool.
- Try a second set of values to compare options.
Worked example
At 20 words per minute a dit lasts 60 milliseconds and a dah lasts 180 milliseconds. The message CQ CQ DE TEST therefore takes only a few seconds, but at 5 words per minute the same message takes four times as long, which is why slow-speed practice nets need generous time slots.
Practical tips
Use the timing numbers to set a practice drill that fits a fixed slot, and check that a beacon message plus its pause fits inside its assigned window. If a message feels rushed on the air, drop the speed by a few words per minute rather than squeezing the gaps, because squeezed gaps are what make copy hard.
Common mistakes
A common mistake is counting only the dits and dahs and forgetting the gaps, which hold a large share of the total time in a long message. Another is assuming words per minute means letters per minute, when the standard word PARIS is what the speed figure is actually based on.
Questions and answers
Is this tool free? Yes. It runs in your browser, needs no account, and gives instant results.
Do I need to install anything? No. The tool works on any modern phone or computer browser.
How accurate are the results? The maths follows the standard formulas shown above. Real-world results vary with terrain, equipment, and conditions, so use the figures for planning.
Can I use it on my phone? Yes. The tool is designed to work on a phone screen, so you can use it at the operating desk, in the field, or at a club station without a computer.
Who uses this tool
Radio amateurs, students, and club members all use tools like this one, because they turn a formula from a book into an answer for your own station in seconds. Beginners use it to check homework and first setups, while experienced operators use it to sanity-check a plan before spending money on cable, masts, or antennas. Even a quick check can prevent a costly mistake, such as ordering the wrong cable length or aiming a beam in the wrong direction.
What to try next
- Run the tool with your real station values, not just the default numbers, so the answer means something for your setup.
- Change one input at a time and watch how the result moves, because that shows you which input matters most.
- Write the result in your station notebook next to the date, so you can compare later changes against a known baseline.
Safety note: this is an educational estimator only. Real transmissions need an amateur licence and must follow your local regulations, band plans, and power limits. Never transmit without the proper licence, and treat every result here as a planning guide, not professional or legal advice.
Versión en español: Calculadora de Tiempo de Código Morse – Duración de Dit, Dah y Mensajes a Cualquier WPM