EVTripPlanner is great for detailed, very-precise estimates of rated miles needed for trip. It includes all the elevation, road speed data, etc into its calcs.
If you just want to do a quick, reasonably accurate estimate of "will I get there", remember that for most driving, it is net elevation to your destination that matters. You can correct the rated miles in your battery by the difference in altitude between where you are and the destination with the factor of 6 rated miles per 1,000 feet.
To do that,
Supercharger.Info has the elevation of all the Superchargers; to get that info, click on the Supercharger dot, then click on "details". To get your current elevation, there are a number of smart phone Apps that will give you that info. I use "
My Altitude" on an iPhone. Just give it several seconds to estimate a good altitude if you have not been using it for a while or have not been using another GPS app like "Google Maps."
For example, Boulder is at about 5,280 feet. The Silverthorne Supercharger is at 8,760 feet. Silverthorne is 3,480 feet higher or about 21 rated miles of potential energy higher than Boulder. If I leave from Boulder going to Silverthorne, I subtract 21 rated miles from the displayed rated miles in the car to look at how much energy I have to cover the distance; if I drive from Silverthorne to Boulder, I add the 21 rated mile.. From
Google Maps, it's about 78 road miles between Boulder and Silverthorne. Because there is a mix of fast highway driving and slower roads and winds, I will want at least 100 rated miles to cover that distance and 125 would be safer if it's getting colder. Therefore to go from Boulder to Silverthorne, I want at least 121 to 146 rated miles to go up the hill to Silverthorne, but only need 79-104 rated miles to come back down the hill.