If you ran at top speed for an hour on a flat road and compared the energy consumed to that used in a full out bike ride over the same one hour period, on the same flat road, the energy expended would be about the same. Provided you'd conditioned yourself for both equally.
On the hills the same applies so long as you keep pedalling hard on the descents. If you want to know for sure how each ft of climb compares, choose an uphill of about ten minutes duration and run it as fast as you can. Then another day ride it as fast as you can and see in the same period of time how far/high you got. That'll give you a comparative and a ratio. But only for that gradient.