Okay, since it seems this question was never asked on this site. Which burns more calories on a treadmill, walking on incline or running on flat?
The best way to tell is go do both of them and see, it will tell you on the screen.
There can be different answers to this. It's going to depend on what incline and speed as opposed to how fast you are running flat.
It really comes down to what your goals are.
If you just want to burn a bunch of cals up, run on an incline, it will burn more than running flat.
At the opposite end of the scale, if you want to burn cals while preserving muscles, go full, slow incline.
I prefer preservation of muscles so I do mine at a 15 degree incline @ 1mph. I don't hold on to anything and keep myself at the bottom. It almost looks like walking in slow motion. I can go slower but the cals burnt are minimal. 1mph is good with me. It's around 275 cals for an hour.
HDH