Calorie Deficit Calculator — How Many Calories to Lose Weight

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.

Quick answer

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.

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Calorie Deficit Calculator

Maintenance • Target • Projection

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Enter your details to see your plan

How to Use the Calorie Deficit Calculator

  1. Enter your stats — gender, age, height and current weight (switch units any time).
  2. Set your goal weight and activity level.
  3. Pick a pace — 1 lb per week is the most sustainable for most people.
  4. Read your plan — your maintenance calories, daily target, and a chart projecting your weight to goal.

Why Use This Calculator

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Science-based

Uses the Mifflin-St Jeor equation — the formula clinicians and dietitians rely on for BMR and TDEE.

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Visual plan

A colorful chart shows exactly how your weight is projected to drop week by week to your goal.

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100% private

Everything runs in your browser — your health data is never uploaded or stored.

Understanding Calorie Deficit and Weight Loss

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.

Calorie Deficit FAQ

Subtract a deficit from your maintenance calories (TDEE). A 500-calorie daily deficit loses about 1 lb per week. Enter your details above and the calculator shows your exact target, but most adults land between 1,200 and 2,000 calories per day for weight loss.
1,200 calories is generally considered the lowest safe intake for women (about 1,500 for men) without medical supervision. Eating too little slows your metabolism, costs you muscle, and is hard to maintain. If your target falls below these levels, choose a slower pace or increase activity instead.
Divide the pounds you want to lose by your weekly pace. To lose 20 lb at 1 lb per week takes about 20 weeks. The chart above plots your projected weight to your goal date. Real progress is rarely perfectly linear — expect faster early loss (water) and occasional plateaus.
BMR is the calories your body burns at complete rest to keep you alive. TDEE is BMR plus the calories burned through daily activity and exercise (BMR × an activity factor). You lose weight by eating below your TDEE.

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✔ Reviewed by the True Value Calc editorial team🗓 Last updated June 2026📚 Sources: CDC, NIH, USDA Dietary Guidelines