How many calories should I eat a day?

There is no single right calorie number - there is a right number for your body and your day. The standard estimates: adult women generally maintain weight on about 1,600 to 2,400 calories a day and men on 2,000 to 3,000, with the low end for smaller, older, or sedentary people and the high end for larger, younger, or very active ones. Those ranges come from federal dietary guidance and are starting points, not targets. For a personalized number, the NIDDK Body Weight Planner is the useful tool - enter your size, age, sex, and activity and it estimates what maintains your current weight and what a realistic change would do over time. It beats generic charts because it adjusts as your weight changes. Practical guardrails: to lose weight, a deficit of roughly 500 calories a day produces about a pound a week - aggressive cuts below 1,200 for women or 1,500 for men without medical supervision tend to backfire through muscle loss and metabolic slowdown. Quality matters as much as quantity: 300 calories of protein and vegetables keeps you full far longer than 300 of soda. And if you are pregnant, under 18, an athlete in heavy training, or managing a medical condition, generic numbers do not apply - that is a clinician conversation. Pymander is a free AI doctor, 24/7 by text. Give it your stats and goal, and it can walk you through a sensible target.