The amount of calories you burn off when walking a mile uphill depends on your current weight but on average you burn off 100 to 110 calories for every mile you walk.
And walking uphill helps you burn off more calories than you would just walking without going uphill because the uphill walk is more strenuous.
You should be burning at least 100 calories when walking uphill a mile and if you walk uphill 1 mile and then walk downhill the other mile you should burn off 200 calories or 220 calories.
Walking in general is a good exercise to keep your body healthy and keep your body able to move as well as improving your heart health.
But walking uphill is much better because it works your body and heart more which is a good thing to keep your heart strong and healthy.