The distance from Vancouver to Calgary is 1057km (660 miles). How long it takes depends on how fast you drive, how often you stop, how you go and when. But I've done it non-stop once and I think it took 14 hours. Possibly more, I don't really remember and it was early April and there was a blizzard in the Rockies that slowed me down. Judy from Calgary has some very good itineraries if you are looking to tour the area enroute. Do a seach and you should find lots of great info.
Found her website for you:
It takes about 12 hours--it isn't the distance, per se, but the route through the mountains that takes the time; it is very busy in the summer and can be slow going. We will often drive from Vanc. to Salmon Arm (about 5 hours with stops) and then Salmon Arm to Calgary (about 6.5 hours with stops). Sometimes we stay in Kamloops, which is one hour before Salmon Arm. There are other stop off options, such as Kelowna, Revelstoke depending on which roads you take and if/how you want to break up the drive. You also lose an hour when changing time zones heading east.
Add more time if driving in winter and be fully prepared to stop for snowstorms, avalanches, mud slides, etc.
Despite the fact that we drive this very often, we still hesitate to drive through the mountains during the night, in any season. During the summer, the sun is up from about 5:15 to about 9:30 p.m. (approximately +/-) so the drive can be done in one day, if you prefer.
One other point is that a time change occurs about half way between Rogers Pass and Golden BC (Pacific to Mountain Time Zones).
12 hours. The first slow stretch is in getting out of Vancouver to Mission. The toll road will help you catch up. After that you will be at the mercy of semi and RVs in the climb. Once in Alberta, it would be a release phenomenon until you get close to Calgary.
To get ahead of traffic, it would be best to start leaving Vancouver by 6am.
We drive to Vancouver from Calgary, and then back of course, at least twice a year. On a good day it takes about 12 hours, on a bad day... well there's no telling. To be honest it's been years since we've done the whole trip in one day. We always end up stopping off in Kelowna on the way (4 hours from Vancouver, 8 hours from Calgary) and spend a night or two. Before we used to be really lazy and stop the night in Revelstoke (4 hours from Calgary, 8 from Vancouver) and then another night in Kelowna, and then proceed to Vancouver!
Well, anyways, it's a beautiful drive. Very few things beat the Canadian rockies... you'll definately enjoy it.