|The word PARIS is the standard
for determing CW code speed. Each dit is one element,
each dah is three elements, intra-character spacing
is one element, inter-character spacing is three
elements and inter-word spacing is seven elements.
The word PARIS is exactly 50 elements.
Note that after each dit/dah of the letter P --
one element spacing is used except the last one.
After the last dit of P is sent, 3 elements are
added (Inter-Character). After the word PARIS
- 7 elements are used.
P = di da da di = 1 1 3 1 3 1 1 (3) = 14 elements
A = di da = 1 1 3 (3) = 8 elements
R = di da di = 1 1 3 1 1 (3) = 10 elements
I = di di = 1 1 1 (3) = 6 elements
S = di di di = 1 1 1 1 1  = 12 elements
Total = 50 elements
() = intercharacter
 = interword
If you send
PARIS 5 times in a minute (5WPM) you have sent
250 elements (using correct spacing). 250 elements
into 60 seconds per minute = 240 milliseconds
13 words-per-minute is one element
every 92.31 milliseconds.
The Farnsworth method sends
the dits and dahs and intra-character spacing
at a higher speed, then increasing the inter-character
and inter-word spacing to slow the sending speed
down to the overall speed. For example, to send
at 5 wpm with 13 wpm characters in Farnsworth
method, the dits and intra-character spacing
would be 92.3 milliseconds, the dah would be
276.9 milliseconds, the inter-character spacing
would be 1.443 seconds and inter-word spacing
would be 3.367 seconds.