It is a really useful tool. The TDEE calculator works out how many calories you burn per day, including your daily activities and exercise. It first calculates your basal metabolic rate (BMR) – the calories you need to stay alive at rest. The calculator then adds in the calories you burn through physical activity to give you an overall picture. Using the tdee calculator, you can easily tailor your diet to your goals. If you want to lose weight, the calculator will help you understand how many calories you need to cut. For gaining weight, on the contrary, you need to increase them. It’s a great way to be more conscious about your diet and training. I hope this helps!