Counting exersice calories

I run on my treadmill for like an hour daily. 250-300 cals.

when i write the speed and time on CC it gives me 500 calories instead. which one is more accurate? 'cause the difference is quite big?

Where are you getting the 250-300-calorie figure? Depending on your weight and speed, I'd think the 500-calorie estimate is more accurate. Also, an hour a day seems excessive. Even if you're training for a race, you need to take a few days to rest and allow your muscles to recover. Running excessively puts you at risk of knee and other injuries, which can sideline you for weeks at a time -- trust me!

I have encountered this same problem today as a matter of fact. I was at the gym earlier and was on the elliptical machine for 70 minutes. It calculated my calorie burn at 875 calories, I plugged it in here and it was over 1000.....same for the treadmill work I did today, it came back +250. I reduced the intensity and/or time to coordinate with what the machines said since I punched my weight in on the machine. I just see it as better safe than sorry so I take the lower number.

The machines at the gym are notoriously bad at estimating calories burned.  Unless you enter in information about your age, height, weight, MHR, etc. then they figure you are an average person of ~150 pounds.  Ones that take your weight into account are better, but still may not be right. 

That's great if you are average, but the count on here is based on the information you input, so it is likely more accurate. 

If you want a more accurate estimate then buy a heart rate monitor. 

The rule of thumb for walking/running is 100 cal per mile.  This would be for a 150 lb person.  A heavier person would burn slightly more.

thank you everyone for replying :)

Katehoo i already have 4 days a month where i have to work for 24 hours so i'm not on the treadmill those days. and of course not when i sick. so i think i workout 3 weeks/month.

and I think it's true the treadmill's burn metre is inaccurate