Resource for determining eleveation

[fuzzy]

Outside of working it out on OS maps (eyes are failing and struggle to read contour markings) is there an on line resource for determining elevation of a given point?

I have recently purchased a Bryton Rider 21T and want to enter the precise elevation of the start point of 99% of my rides- my front gate.

[Pedal Castro]

I was thinking about this yesterday. I would trust spot heights, but just how accurate are contour lines? 

[fuaran]

I think the contour lines on the 1:25K maps are usually pretty accurate. If you have Memory Map or similar, you can zoom in on the map to read them.
Though you do have to consider the height datum. Heights on OS maps use Ordnance Datum Newlyn, whereas GPS devices usually use WGS84, which is rather different.

If you have a GPS device, you could use that to measure the elevation. It should be fairly accurate, if it has a clear view of the sky and if you leave it for a while. Most Garmins have an option for "waypoint averaging", where it will take a number of readings over several minutes, then average them. Don't know if the Bryton has anything similar?
If you repeat this a few times, on different days, you can take an average of all of your measurements, which would probably be within a few metres of the 'correct' elevation.

[Pedal Castro]

Just looked it up, Ordnance Survey themselves say the contour lines are likely to be accurate to at least ±3 m.

[zacklaws]

Theres a few websites that you get your actual elevation, but as daft as it is, I cannot think of any apart for one that I have not used for ages which I used to use to get a profile up a hill. If you go to satellite view and click on the spot you want it will give you your elevation but according to what it gives me its 10 foot out from what Ordnance survey Memory Map on my computer gives me which is +/- 3mtrs I suppose

http://www.heywhatsthat.com/profiler-0904.html

As for leaving a GPS turned on, my 800 never gives me the correct altitude and I always turn it on 15 mins before a ride to stabilise itself, but the trick is to make your departure point a location with the correct elevation recorded as well. Soon as I press "Start" and cross over my departure point, my driveway, the elevation recalibrates itself to that point. But would a Bryton do that?

[fuaran]

Probably best to use a GPS device without a barometric altimeter for this.

[frankly frankie]

Draw a very small fragment of Track outside your front door using BikeRouteToaster then switch to the 'Summary' tab and read off the Start and Finish elevations (which should be nearly the same, if the Track is short enough).

[fuzzy]

ff, that is exactly what I was looking for. The track gives 36m as the start and finish elevation. My struggle with OS map contours suggested 35m

[Ningishzidda]

ff, that is exactly what I was looking for. The track gives 36m as the start and finish elevation. My struggle with OS map contours suggested 35m

Wow. You'd better pray to high heaven that ice sheet doesn't fall off Antartica.