Find your daily calorie target to lose weight safely. Enter your details to see your maintenance calories (TDEE), your deficit target, and a projected weight-loss chart to your goal.
A calorie deficit means eating fewer calories than you burn. To lose one pound of fat you need roughly a 3,500-calorie deficit, so a 500-calorie daily deficit yields about one pound of weight loss per week. This tool finds your maintenance calories and target deficit.
Maintenance • Target • Projection
Uses the Mifflin-St Jeor equation — the formula clinicians and dietitians rely on for BMR and TDEE.
A colorful chart shows exactly how your weight is projected to drop week by week to your goal.
Everything runs in your browser — your health data is never uploaded or stored.
A calorie deficit means eating fewer calories than your body burns, which forces it to use stored fat for energy — the only proven way to lose weight. Because roughly 3,500 calories equals about one pound of fat, a deficit of 500 calories a day produces about one pound of loss per week, while 250 a day yields half a pound and 1,000 a day about two pounds.
This calculator first estimates your Basal Metabolic Rate (BMR) — the energy you burn at rest — with the Mifflin-St Jeor equation, then multiplies it by an activity factor to get your Total Daily Energy Expenditure (TDEE), the calories you burn in a typical day. Subtracting your chosen deficit gives the daily calorie target that will move you toward your goal weight, and the chart projects how long it should take at that pace.
How fast should you lose weight? Most health authorities, including the CDC, recommend a steady 1 to 2 pounds per week. Faster loss often means losing muscle and water rather than fat, and is harder to sustain. This tool will warn you if your target drops below a safe minimum (about 1,200 calories for women and 1,500 for men); going lower should only be done under medical supervision.
Tips to hit your deficit: prioritize protein to preserve muscle and stay full, fill up on vegetables and fiber, drink water before meals, track portions for a few weeks to calibrate, and combine diet with strength training and daily movement. Remember these numbers are estimates — your real results depend on consistency, sleep, stress and individual metabolism. This calculator is for general information and is not medical advice; consult a doctor or registered dietitian before starting any weight-loss plan.
Fat loss requires eating less energy than you spend, and the conversion rule most calculators use is that a pound of body fat stores about 3,500 calories. That figure comes from Max Wishnofsky's 1958 paper and is a useful approximation over weeks rather than a law. It overstates long-run loss because it assumes the deficit stays constant, when in reality a lighter body burns fewer calories — so a deficit that produced a pound a week in month one produces less by month four unless intake is revised downward. It also ignores that early weight loss is substantially water and glycogen, which is why the first fortnight always flatters the arithmetic.
Daily deficit = TDEE − IntakeWeekly loss (lb) = (Daily deficit × 7) ÷ 3,500Weekly loss (kg) = (Daily deficit × 7) ÷ 7,700where:
Assumptions: A linear approximation valid over weeks, not months. Recalculate TDEE after every 5–10 lb lost. Deficits beyond about 25% of TDEE increase lean-mass loss without proportionally speeding fat loss, and are harder to sustain.
Someone with a 2,424-calorie TDEE eats 1,924 a day. What happens over twelve weeks?
ResultAbout 1 lb a week — roughly 10–11 lb over 12 weeks after adaptation
This is why plateaus are structural rather than a failure of willpower: the same intake that created a deficit at the start becomes maintenance at a lower weight. The fix is to recalculate every 5–10 lb rather than to cut ever harder.