There is a map with line distance numbers:
Inner Sphere Stellar Cartography Project. Other maps might provide
Jump route distances, like MekHQ, which is a discrete value that you might be interested in if your not Jumping 'as the crow flies', which is rarely done*. ISCP has (or did have) data files available to justify the calculations. They might have the same sources as Sarna.
FYI: 30/60ly visual scale;
30 light years and 60 light years have special significance because they are JumpDrive ranges.
The HPG communication range is 50 light years and probably close enough to 60 (for a visual representation box and general scope of relevant nearby systems) to be the convenient scale to use by default.
*Except for LF battery equipped ships, which might jump to deep space on the first leg of a double jump, the significant risk of winding up lost forever, in that 'deep space' off of the known routes, prompt ship captains to restrict routing, (except in the most dramatic circumstances, you figure, right?) so that the recharge cycle happens somewhere close enough to human habitation for a distress call.