Safely losing about one pound per week requires a daily calorie deficit of 500 below your Total Daily Energy Expenditure (TDEE), which translates to roughly 1,500 calories per day for the average woman and 2,000 for the average man.
The question “how many calories do I need to lose weight” has a specific number—one that varies from person to person. The math is straightforward: a pound of body fat holds about 3,500 calories, so trimming 500 calories from your daily needs drops roughly a pound each week. But the real work is finding your exact calorie target, because the average ranges only get you started.
Below you’ll find the two formulas that calculate your personal number, a quick-reference table for common profiles, and the four steps that turn the math into steady, sustainable weight loss.
How To Calculate Your Personal Calorie Target
Your daily calorie needs depend on three factors you can plug into an equation: your current weight, height, age, and typical activity level. The most accurate formula used by medical professionals is the Mifflin-St. Jeor equation, which calculates your Basal Metabolic Rate (BMR)—the calories you’d burn at complete rest—then multiplies by an activity factor to get your TDEE.
Here are the BMR formulas and the activity multipliers that turn them into your personal target:
BMR Formulas (Mifflin-St. Jeor)
These equations tell you how many calories your body burns just staying alive—breathing, circulating blood, maintaining organs. Convert your pounds to kilograms (multiply by 0.45) and your inches to centimeters (multiply by 2.54) before plugging them in.
- Women: (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) − 161
- Men: (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) + 5
Activity Multipliers To Find Your TDEE
Once you have your BMR, multiply it by the factor that best matches your daily activity to find your total daily energy expenditure—or maintenance calories:
- Sedentary (little or no exercise): BMR × 1.2
- Lightly Active (1–3 days per week of light exercise): BMR × 1.375
- Moderately Active (3–5 days per week): BMR × 1.55
- Very Active (6–7 days per week): BMR × 1.725
- Extra Active (strenuous daily exercise or physical job): BMR × 1.9
To lose weight, subtract 500 from your TDEE result. That number is your daily calorie budget for a safe loss of about one pound per week.
Calorie Deficit Target By Profile
Not everyone wants to run the math. The table below gives weight-loss targets for the most common profiles using the Mifflin-St. Jeor formula and a moderately active lifestyle multiplier.
| Profile | Maintenance Calories (TDEE) | Weight-Loss Target (deficit of 500) |
|---|---|---|
| Woman, 150 lbs, 5’4″, age 30, lightly active | ~2,050 cal | ~1,550 cal |
| Woman, 180 lbs, 5’6″, age 45, sedentary | ~1,800 cal | ~1,300 cal |
| Man, 200 lbs, 5’10”, age 35, moderately active | ~2,900 cal | ~2,400 cal |
| Man, 250 lbs, 6’0″, age 50, sedentary | ~2,350 cal | ~1,850 cal |
| Woman, 130 lbs, 5’2″, age 25, very active | ~2,200 cal | ~1,700 cal |
| Man, 175 lbs, 5’8″, age 40, moderately active | ~2,600 cal | ~2,100 cal |
| Woman, 220 lbs, 5’7″, age 60, sedentary | ~1,750 cal | ~1,250 cal |
Important: Women should not drop below 1,200 calories daily, and men should not go below 1,500, unless under medical supervision. These minimums exist to ensure your body gets the nutrients it needs to function.
How To Start A Calorie Deficit The Right Way
The math only works if you track what you actually eat. Studies consistently show that people underreport portions by 20–40% when they estimate by eye. The CDC’s standard protocol breaks it into manageable steps that most people can sustain long-term.
Step 1: Track your baseline. For one week, write down everything you eat and drink—use a notebook, a phone app, or a simple notes file. Be honest; you’re collecting data, not judging yourself. Record portion sizes by weight if possible using a kitchen scale, especially for calorie-dense foods like nuts, oils, and cheese.
Step 2: Set 2–3 short-term goals. Don’t aim for the full 500-calorie cut starting tomorrow. A realistic opening goal might be “replace the afternoon soda with sparkling water” or “reduce dinner portions by 20%.” Focus on small wins you can stack.
Step 3: Use the right tools. A food scale, a calorie-tracking app (most reputable ones have extensive databases), and measuring cups. The NHS specifically recommends weighing portions early on so you can eyeball accurately later.
Step 4: Follow one portion control strategy. Eat from plates, not packages. Use smaller bowls. Check the Nutrition Facts panel for serving sizes—a bag of chips labeled 150 calories may actually be two servings, not one.
The CDC’s weight-loss protocol provides full guidance on setting goals, finding support, and monitoring progress without falling into common traps.
Portion Clues That Make Or Break Your Deficit
Calorie deficits fail more often from portion confusion than from bad food choices. Here are the fast rules that fix the biggest mismatches between what you think you’re eating and what you’re actually eating:
- A serving of meat is about 3–4 ounces—roughly the size of a deck of cards or the palm of your hand (not including fingers).
- A serving of rice or pasta is about half a cup cooked—roughly the size of a cupped hand or a tennis ball.
- A serving of peanut butter is two tablespoons—about the size of a ping-pong ball, not a heaping soup spoon.
- Restaurant entrees often serve 2–3 servings of protein and 3–4 servings of carbohydrates. Either share the plate or box half for tomorrow’s lunch before you start eating.
- Prepackaged “healthy” meals can pack surprising fat, sugar, and salt to improve flavor—read the label, not the front-of-box marketing.
The Maintenance Break Strategy
Smart calculators recommend a cycle approach: maintain your calorie deficit for 6–12 weeks, then increase your intake back to maintenance for another 6–12 weeks. This pause helps reset hunger hormones and prevents the metabolic slowdown that makes extended deficits feel impossible. It is not a setback—it is part of the strategy that keeps weight loss sustainable.
During your maintenance phase, use the same TDEE formula but do not subtract the 500-calorie deficit. Focus on eating to your exact TDEE number, continue tracking portions, and let your body settle before starting a new deficit cycle.
Common Mistakes That Sabotage The Deficit
Even with perfect math, the wrong choices can stall progress. Watch for these five traps that steal results without adding much satisfaction:
- Dropping below the minimum threshold. Women eating under 1,200 calories or men under 1,500—unless directed by a doctor—risk nutrient deficiencies and a slowed metabolism.
- Setting the deficit too steep. A 1,000-calorie daily cut (2-pound weekly loss) sounds twice as fast but is harder to sustain long-term. The 500-calorie route keeps success rates higher.
- Eating simple carbs instead of fiber-rich ones. White bread, white rice, and regular pasta digest quickly and leave you hungry again in an hour. Swapping to brown rice, quinoa, or whole-wheat pasta adds fiber that keeps you full longer.
- Misjudging your activity level. Most people overestimate how much they move. The “moderately active” multiplier requires deliberate exercise 3–5 days per week, not a busy lifestyle that includes parking at the far end of the lot.
- Ignoring liquid calories. Coffee with cream, sodas, juices, and alcohol add up fast without registering as “eating.” A single 200-calorie latte matters as much as a 200-calorie snack.
Your Calorie-Deficit Quick-Start Checklist
- Calculate your BMR using the Mifflin-St. Jeor formula above.
- Multiply by your correct activity factor to get your TDEE (maintenance calories).
- Subtract 500 from your TDEE—that is your weight-loss daily target.
- Verify your target is above the safe minimum (1,200 for women, 1,500 for men).
- Track every bite and sip for one week using a food scale and an app or notebook.
- Set 2–3 specific, small goals for week one instead of overhauling everything.
- Plan to eat from reasonable plates and check Nutrition Facts labels on everything.
- Schedule a maintenance-break week after 6–12 weeks at deficit.
Follow that list and the math takes care of the pounds—you just have to execute the tracking.
References & Sources
- CDC. “Steps for Losing Weight” Outlines the official protocol for setting goals, tracking, and monitoring weight loss.
