If you want to lose 40lbs and are burning over 600 calories everyday and eating right how long would it take?

The really simple answer is that most people can lose anywhere from 1 - 2 pounds a week with a reasonable diet or exercise plan, so 20-40 weeks, or 140 - 280 days before you reach your goal weight.

Now for the more complicated answer. First as a disclaimer, for any of this to be relevant you need to calculate your daily calorie needs. Weight gain or loss all comes down to math (energy in vs. energy out) and you need to know as many of your variables as possible for an accurate prediction.

How many calories your body needs to run itself during the day vary depending on a number of factors including age, height, weight, and gender, but let's just pick 2,000 to use as an example. If you ate 2,600 calories a day, but then burned an extra 600 through exercise you would neither gain nor lose weight since Energy In (2,600) - Energy Out (2,000 + 600) = 0, leaving you with no net calorie gain or loss.

You say that you want to lose 40 lbs, and since 1 lb = 3,500 calories, you have 140,000 calories that you need to lose total. The number of days until you reach your goal will be equal to 140,000 divided by your daily calorie deficit.

If you ate exactly your required number of calories a day, and then burned an extra 600 calories on top of that, you would get this equation:

Energy In (2,000) - Energy Out (2,000 + 600) = - 600.

# Days until Goal = 140,000/600 = 233 days

You say that you are eating right, which could mean that you are either eating exactly what your body needs or even a little bit less. If you are eating 100 calories less than you need a day and exercising then the equation would be this:

Energy In (1,900) - Energy Out (2,000 + 600) = - 700

# Days until Goal = 140,000/700 = 200 days

If you are eating 200 less and exercising you'd get this:

Energy In (1,800) - Energy Out (2,00 + 600) = -800

# Days until Goal = 140,000/800 = 175 days

You can keep playing with the numbers to get different answers depending on how restrictive you are being with what you eat, but this should give you at least a rough weight losstimetable.