Finding Elevation Change, any method So, I think it'd be cool - for goal setting for example - if I could keep track of my elevation change.

The problem is, the local cyclocomputers I looked at seem to use barometric pressure to determine the change.  This is fine, unless some weather is moving in, which happens not infrequently in the Midwestern United States.

Or do some of them try to use an inclinometer, your speed, and some math you learn in Calculus II to keep track of your change?  That would seem more accurate!

I could try to use a GPS meter, but those things are expensive -  and based on back when I had service to my smart phone, not guaranteed to match my car's odometer for distance even - I've read from some other riders that the distance varies at least slightly from local measurement on a bike as well. 

Alternatively, let's say that I ride along a known route.  Is there any good way of plotting that route for elevation change?

Thanks!
The simplest on-the-road solution is to get a detailed paper (walker's?) map with contour lines. In the UK, Ordnance Survey provide these, for the USA you could try Omnimap.

Alternatively, there are plenty of online tools, like freemaptools.com which use Google Maps. You click on a point and it gives you the elevation.