Start from maintenance, then make a small change
The example above is a 42-year-old woman, 5′5″ and 185 lb, who is lightly active. Her estimated maintenance is about 2,063 calories a day. A gap of 250 to 500 calories gives a starting target of roughly 1,563 to 1,813. Smaller gaps mean slower change, but they are usually easier to live with and to keep up.
Why not go lower? Bigger deficits tend to bring more hunger and fatigue, make it harder to get enough protein and nutrients, and are harder to sustain. Slow, steady change that fits your life usually works better in the long run.
Your TDEE changes as your weight changes
If the same woman reaches 170 lb, her estimated maintenance drops to about 1,969 calories, around 94 lower than before. That is one reason weight change slows over time even when habits stay the same. Recalculate every 10 lb or so, and judge progress by your average weight over several weeks rather than any single day.
When to get personal advice
A calculator can’t see your health history. Please check with a doctor or registered dietitian if you have a medical condition or take medication that affects weight or appetite, if you are pregnant or breastfeeding, if you are under 18, or if your target would be very low. If food, eating or your body has been feeling hard to manage, you’re not alone, and support is available: the National Alliance for Eating Disorders runs a free helpline staffed by licensed therapists.
Frequently asked questions
How do I use my TDEE to lose weight?
Eating somewhat less than your TDEE creates an energy gap that the body covers partly from stored energy. A modest gap of about 250 to 500 calories a day is a common, gentle starting point, often linked to roughly 0.5 to 1 lb a week at first. Results vary, and change usually slows over time.
Why doesn’t this calculator show bigger deficits?
Larger cuts are harder to sustain and more likely to leave you short of nutrients and energy. If a gentle target would already fall below about 1,200 calories a day for women or 1,500 for men, we show a note instead of a number, because at that point a doctor or registered dietitian is the right guide.
Is the 3,500-calories-per-pound rule accurate?
It is a rough rule for the first weeks. Over longer periods it overstates weight change, because as weight goes down, the body uses less energy. That is why it helps to recalculate every 10 lb or so and judge progress by your multi-week trend.
Should I eat back calories from exercise?
If you picked an activity level that already includes your workouts, no. If you chose “sedentary” and log workouts separately, adding some back is reasonable, but fitness-tracker estimates often run high, so many people add back only part.