Deficit math checked against the 3,500-calorie-per-pound rule of thumb cited below.
To lose about a pound a week, eat roughly 500 calories below your Total Daily Energy Expenditure. For most adults that lands somewhere between 1,400 and 2,200 calories a day, depending on size and activity level. Two pounds a week needs a 1,000-calorie deficit, which is aggressive and only realistic for people whose TDEE is high to begin with.
The arithmetic behind the pound-a-week rule
A pound of body fat holds roughly 3,500 calories. Cut 500 a day and the weekly total works out to that same 3,500, which is where the "one pound a week" figure comes from. In practice the rate slows as you lose weight, because TDEE drops along with body mass, so the calculator at the top of this page recalculates as your inputs change rather than locking in day one's number.
Deficit sizes and what they actually cost you
| Goal | Daily deficit | Expected loss | Notes |
|---|---|---|---|
| Slow, sustainable | 250-300 cal | ~0.5 lb/week | Easier to hold onto muscle |
| Standard | 500 cal | ~1 lb/week | Best starting point for most |
| Moderate-aggressive | 750 cal | ~1.5 lb/week | Needs a high enough TDEE |
| Aggressive | 1,000 cal | ~2 lb/week | Not realistic for lighter people |
These are population averages, not a promise. Metabolism, body composition and how closely you actually stick to the number all move the real result.
Why the same deficit gives different targets by sex
Women typically carry less lean muscle and a smaller frame, which pulls TDEE down. A sedentary 140-pound woman might sit around 1,700 calories TDEE; a moderately active 190-pound man might be closer to 2,800. A 500-calorie cut then means 1,200 for her and 2,300 for him, which is exactly why a single "eat 1,500 calories" chart floating around the internet is nearly useless without knowing whose body it was written for.
The floor most plans shouldn't go below
Dropping under roughly 1,200 calories for women or 1,500 for men without medical supervision tends to backfire: it's hard to hit protein and micronutrient targets, and the body responds to a large, sustained deficit by slowing its resting burn rate. See whether 1,200 calories fits your situation before treating it as a default.
Stalled at 1,400 calories? Check these first
The usual suspects: TDEE was overestimated to begin with, tracking has quiet gaps (cooking oil, sauces, a handful here and there), or a few weeks of water retention is masking real fat loss. Give a new number 3 to 4 weeks before deciding it isn't working, and if it truly stalls, recheck your TDEE or talk to a registered dietitian.
Run your own numbers
The calorie deficit calculator turns your height, weight and activity level into a personal TDEE and target intake.