try one of the map sites, such as:
http://www.viamichelin.com/viamichelin/gbr/dyn/controller/HomePage
http://www.shellgeostar.com/share/

Josephine,

This is the url for a driving distance calculator between Irish cities.

http://www.irish-insight.com/distances.html

Consider though that the route you take, whether scenic or direct will greatly affect your times. I will say that I felt that the view between cities surpassed the sights at the end destination. Then again, I do enjoy the countryside. We took a really enjoyable drive down the Military Road through the Wicklow Mts south of Dublin and a walk through at Glendalough, which added a few hours to the drive. All in all, I enjoyed it more than Kilkenny itself.

Also, if you get off the main roads, the road size and quality will certainly add time (but quality) to your trip.

I like to use www.theaa.com
they have a pretty good route planner.
and from what I can tell, the TIME they list is pretty accurate.
(i.e. - Shannon -> Doolin via the Cliffs is about 44 miles but will take at least 1hr 10min. - actually closer to 90 min, but pretty close) .

Another suggestion - after you get your guestimates, check with the expert ( Pat at www.irelandexpert.com, on her forum) she will set you straight on how long it takes to get from A to B.

another website - mapblast.com - can be useful for planning road trips in many countries

Josephine,

Travel writer Rick Steves has suggested that a visit to Ireland will lead the visitor to cast his or her itinerary to the sea. In other words, don't get too hung up on actual distances between cities, as you'll no doubt want to engage in spur-of-the-moment stops, spending an hour or two (or even more) at unexpected places of interest.

Still, if its approximate distances you want, you can travel from Dublin to Kilkenny in about two hours. Do note, however, that should you do it in that time, you'll miss some lovely Co. Wicklow and Kilkeny countryside.

Waterford is at least another hour from Kilkenny. The Waterford coastal drive, by the way, is quite attractive and non-touristy.

Finally, the direct route from Killarney to Limerick is probably two to three-hours drive (on the N21). You might consider spending a couple hours in Adare, on route to Limerick. Many people find Adare quaint, evoking a thatched roof Ireland of their dreams. Others, meanwhile, find it too touristy (The Rough Guide to Ireland calls it prissy.) As an alternative, consider veering off the N21, heading east through Co. Limerick, for Lough Gur. The area features a wealth of neolithic finds, situated on the shores of, or nearby, a lovely and relatively undiscovered lake. Get a good travel guide (like The Rough Guide) to learn more, especially if you're interested in ancient Irish history.

Best of luck.

Hello out there and many thanks to those who responded to my inquiry regarding Ireland mileage. Each of your suggestions warrant follow up, which I am in the process of doing. I'll likely be back with an update. Thanks Bob, Clifton, Debbie, Dad and David!