I'm trying to finalize my itinerary for my 2 weeks in the UK. I'm still having a hard time deciding on my days in the Highlands. I'll have 4 days. And I'm deciding between staying all in one area, or moving place to place each day. Realistically, I need to know how long these routes are.

Edinburgh to Glen Coe?
Inverness area to Edinburgh?

Have you tried ViaMichelin (http://www.viamichelin.co.uk/) or Mappy (http://www.mappy.com/)? They are fairly accurate, at least in France.

For the UK - and especially for first time visitors - I'd add approx 30 - 35% to the drive times on most of the mapping sites. (and a bit more in remote areas due to the single track roads etc)

Also try www.theaa.com (their equivalent of AAA). They have route mapping - and add about 30% to it if you are not a local and used to the roads, just as Janisj said. She knows wherefore she speaks!

Inverness to Edinburgh will probably take most of a day, if you are stopping to see things like Perth or random castles on the way. We went from Whitby (England) to Perth in one day (through Edinburgh) and were near exhausted at the end. The next day up to Inverness seemed much shorter, but was still a couple hours with the side trips.

Inverness to Edinburgh is 150 miles and the road is reasonable but very very busy and if there are heavy lorries using it it can be a long journey. Realistically allow yourself 4 hours plus extra if you intend stopping along the route.
Depending on works and road alterations ongoing at the Forth Road Bridge you could also encounter a slight delay there.

Edinburgh to Glencoe depends on your route. Via Callander is about 3 hours but longer if you intended travelling to Glasgow and then up Loch Lomond to Glencoe. The time will depend on Glasgow traffic so allow at least 4 hours. Obviously you will have to allow longer if you intend having stops along the journey.

When I was new to the UK I would just estimate how long it would take to drive that distance in the US, double it, and it came out pretty close. Perhaps with the heavy traffic we have these days it would be safer to treble.

For example it took us from 9a.m. until 5 or 5:30 p.m. to drive the 110 miles from Craigallichie (sp) in the highlands, through Inverness, past Loch Ness to Oban. We ate obviously and took a few pictures, but didn't dawdle a lot.

Thanks! This helps a lot. I think we're going to stay put in one place. Helps on the packing and unpacking. We're gonna go Edinburgh to Spean Bridge through Glencoe (Bi-passing Glasgow)and base ourselves there. It seems better to base ourselves there than nearer Inverness. Because we do have to get back to Edinburgh on our last day.

Idrive Edinburgh to Oban twice a week. Edinburgh to Tyndrum is 2 hours.
Hope this helps.