According to my endocrinologist, you shouls only consume 200 grams of carbs a day to lose weight.
You might find a BMR calculator and plug in your numbers. I've used one (can't remember which) and in addition to giving a rough estimate on my BMR, it gave the amounts of carbs, proteins and fats in grams and percents. I hope this helps.
TO come up with an average number we would need your weight, height and age. What is your diet like? Do you do any exercise and what? How active are you?