I wouldn't bother about the specific numbers.
On machines, use them as a relative guide to know how much "work done" you've gotten in, either for keeping it stable or to try and better it.
If you want to work on weight loss, keep a track of the weight you are loosing, if you want to loose a bit more, eat a bit less and do a bit more.
If you want fitness, simply try to keep bettering your calorific "score" or the time you can maintain that rate for.
On machines, use them as a relative guide to know how much "work done" you've gotten in, either for keeping it stable or to try and better it.
If you want to work on weight loss, keep a track of the weight you are loosing, if you want to loose a bit more, eat a bit less and do a bit more.
If you want fitness, simply try to keep bettering your calorific "score" or the time you can maintain that rate for.