The Synchro is based on the HCM method of signal cycle calculation.
you can calculate by following way.
The cycle lengths are calculated by SYNCHRO.
Menu Optimise -> Network Cycle Lengths.
Half way down the toolbar are two buttons - circle, arrow and bar. The blue one (Show Cycle Lengths) shows the cycle lengths for the network. The green one (Show Natural Cycle Lengths) are what the cycle lengths would be if the signals weren't linked together.
Clicking the 'Optimise' button for any junction sets the junction to the natural cycle length. This may lead to long queue lengths, now that the signals are not set up as a group.