Most people need to eat 500 to 750 fewer calories than they burn each day to lose weight at a steady, sustainable pace. That typically lands somewhere between 1,200 and 2,000 calories per day, depending on your size, age, sex, and how active you are. But the right number for you depends on a simple calculation you can do yourself.
How to Estimate Your Daily Calorie Needs
Weight loss comes down to eating less energy than your body uses. The total number of calories you burn in a day is called your total daily energy expenditure, or TDEE. To find yours, you start by estimating your resting metabolic rate, the calories your body burns just to keep you alive (breathing, circulating blood, maintaining body temperature). Then you multiply by an activity factor.
The most widely recommended formula for estimating resting metabolic rate is the Mifflin-St Jeor equation. The American Dietetic Association found it was more likely than competing formulas to predict metabolic rate within 10% of what’s actually measured in a lab. Here’s how it works:
- For men: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
- For women: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
If you prefer pounds and inches: multiply your weight by 4.536 to get kilograms, and your height by 2.54 to get centimeters. Or simply use one of the many online calculators that plug in these numbers for you.
Once you have your resting metabolic rate, multiply it by an activity factor based on data from the Food and Agriculture Organization of the United Nations:
- Sedentary or lightly active (desk job, minimal exercise): multiply by 1.4 to 1.7
- Moderately active (regular exercise, active job): multiply by 1.7 to 2.0
- Vigorously active (intense daily training, physical labor): multiply by 2.0 to 2.4
The result is roughly how many calories you burn per day. To lose weight, subtract 500 to 750 from that number. That’s your daily calorie target.
A Quick Example
A 40-year-old woman who weighs 170 pounds (77 kg) and is 5’5″ (165 cm) with a desk job would calculate her resting metabolic rate as: (10 × 77) + (6.25 × 165) − (5 × 40) − 161 = 1,440 calories. Multiply by 1.5 for a sedentary lifestyle, and her TDEE is about 2,160 calories. To lose roughly one pound per week, she’d aim for about 1,660 calories per day.
Why the “500 Calories per Pound” Rule Isn’t Exact
You may have heard that cutting 3,500 calories equals one pound of fat lost. The Mayo Clinic notes this older rule doesn’t hold true for everyone. When you lose weight, you lose a mix of fat, lean tissue, and water, not pure fat. Your body also adapts to the reduced intake, which brings us to one of the biggest reasons weight loss slows down over time.
Research published in the journal Metabolism found that your metabolic rate starts dropping within the first week of calorie restriction, a process called metabolic adaptation. On average, participants burned about 178 fewer calories per day than expected after just one week of dieting. That gap stayed consistent throughout six weeks of calorie restriction. In practical terms, every 100 extra calories per day your metabolism slowed translated to about 2 kg (4.4 pounds) less weight lost over six weeks.
This is why weight loss rarely follows a neat, linear path. A deficit that produces noticeable results in weeks one through four may slow considerably by month two or three. It doesn’t mean something is wrong. It means your body is adjusting, and your calorie target may need a small downward tweak or your activity level may need to increase slightly to maintain the same rate of loss.
How Fast You Should Lose Weight
The CDC recommends aiming for 1 to 2 pounds per week. People who lose weight at that gradual, steady pace are more likely to keep it off than those who drop weight quickly. Aggressive deficits (eating far below your needs) tend to backfire: they amplify metabolic adaptation, increase hunger, and make the diet harder to sustain.
For most people, a deficit of 500 calories per day produces roughly one pound of loss per week in the early stages. A 750-calorie deficit nudges closer to 1.5 pounds per week. Going much beyond that without medical supervision is rarely worth it.
The Calorie Floor You Shouldn’t Go Below
No matter what the math says, there’s a minimum threshold. Women should not eat fewer than 1,200 calories per day, and men should not go below 1,500, unless specifically guided by a doctor or dietitian. Below those levels, it becomes very difficult to get enough essential nutrients from food alone. Your metabolism also slows more aggressively when your body senses it isn’t getting enough fuel, which makes the deficit less effective over time anyway.
If your calculated target falls below those floors, it’s a sign you should rely more on increasing physical activity to create part of the deficit rather than cutting food intake further.
What to Eat Within Your Calorie Target
The number of calories matters, but so does what makes up those calories. The most recent Dietary Guidelines for Americans (2025-2030) keep the message straightforward: prioritize whole, nutritious foods and limit highly processed foods, added sugars, and refined carbohydrates.
Protein is especially important during a calorie deficit because it helps preserve lean muscle mass, the tissue your body is most tempted to break down alongside fat. Spreading protein across meals (rather than loading it all into dinner) keeps you feeling fuller throughout the day. A reasonable target for most people trying to lose weight is 0.7 to 1 gram of protein per pound of body weight.
Fiber is the other major hunger-management tool. It slows digestion, stabilizes blood sugar, and adds bulk to meals without adding many calories. The general recommendation is about 14 grams of fiber per 1,000 calories you eat. If you’re on a 1,600-calorie plan, that’s roughly 22 grams per day. Most people eating in a deficit should aim for at least 20 to 25 grams daily. Vegetables, beans, lentils, oats, and berries are among the most fiber-dense foods per calorie.
When Your Progress Stalls
Plateaus are normal. They happen because of the metabolic adaptation described earlier, because your smaller body now burns fewer calories at rest, and sometimes because portion sizes gradually creep up without you noticing. When weight loss stalls for two to three weeks, a few adjustments help:
- Recalculate your target. Plug your current (lower) weight back into the formula. A person who has lost 20 pounds needs fewer calories than they did at their starting weight.
- Track more carefully for a week. Cooking oils, dressings, and snacks are common sources of unnoticed calories.
- Add movement. Even an extra 20 minutes of walking daily can offset some of the metabolic slowdown.
Weight loss is not a one-time calculation. It’s a target you revisit every 10 to 15 pounds, adjusting as your body changes. The people who succeed long-term treat their calorie target as a moving number, not a fixed rule.