Most adults lose weight steadily on a calorie deficit of 500-750 calories per day below maintenance, which typically means eating somewhere between 1,500-2,000 calories daily for women and 1,800-2,400 for men — but the right number depends heavily on your starting weight, activity level, age, and sex. Below is how to calculate your own target, why crash-diet numbers backfire, and how activity level changes the math.
Step 1: Find Your Maintenance Calories First
You can’t set a weight-loss target without knowing your maintenance number — the calories that keep your weight stable. The most common estimate uses the Mifflin-St Jeor equation, which factors in weight, height, age, and sex, then multiplies by an activity factor:
| Activity Level | Description | Multiplier |
|---|---|---|
| Sedentary | Little to no exercise, desk job | 1.2 |
| Lightly active | Light exercise 1-3 days/week | 1.375 |
| Moderately active | Moderate exercise 3-5 days/week | 1.55 |
| Very active | Hard exercise 6-7 days/week | 1.725 |
A 35-year-old woman, 5’5″, 160 lbs, moderately active, lands around 2,100 maintenance calories. A 40-year-old man, 5’10”, 200 lbs, moderately active, lands closer to 2,600. These are estimates, not lab measurements — real-world results over 2-3 weeks are the actual feedback loop that tells you if the number needs adjusting.
Step 2: Subtract for a Sustainable Deficit
One pound of body fat represents roughly 3,500 calories, so a 500-calorie daily deficit works out to about one pound per week — the pace most major health bodies consider sustainable and least likely to trigger the muscle loss and metabolic slowdown that come with more aggressive deficits.
| Deficit Size | Daily Deficit | Approx. Weekly Loss | Sustainability |
|---|---|---|---|
| Conservative | 250 cal | ~0.5 lb | Very sustainable, slow |
| Moderate | 500 cal | ~1 lb | Standard recommendation |
| Aggressive | 750-1,000 cal | 1.5-2 lb | Harder to sustain, higher muscle-loss risk |
Recommended Calorie Ranges by Age, Sex, and Activity Level
These ranges assume a moderate ~500-calorie deficit already applied — they’re a starting estimate, not a prescription:
Women
- 19-30, sedentary to lightly active: 1,600-1,800 calories/day
- 19-30, moderately to very active: 1,800-2,200 calories/day
- 31-50, sedentary to lightly active: 1,500-1,700 calories/day
- 31-50, moderately to very active: 1,700-2,100 calories/day
- 51+, sedentary to lightly active: 1,400-1,600 calories/day
- 51+, moderately to very active: 1,600-2,000 calories/day
Men
- 19-30, sedentary to lightly active: 2,000-2,200 calories/day
- 19-30, moderately to very active: 2,200-2,600 calories/day
- 31-50, sedentary to lightly active: 1,900-2,100 calories/day
- 31-50, moderately to very active: 2,100-2,500 calories/day
- 51+, sedentary to lightly active: 1,800-2,000 calories/day
- 51+, moderately to very active: 2,000-2,400 calories/day
Nobody should go below roughly 1,200 calories/day (women) or 1,500 calories/day (men) without direct medical supervision — below that threshold the body struggles to get adequate protein, micronutrients, and energy for daily function, and weight loss tends to stall anyway as metabolism adapts downward.
Why Crash Diets Backfire
A very large deficit (1,000+ calories) produces faster short-term loss on the scale, but a meaningful share of that early loss is water and muscle, not fat. Losing muscle lowers your resting metabolic rate, which means your new “maintenance” number drops too — the classic mechanism behind regaining weight quickly once normal eating resumes. A moderate, sustainable deficit paired with enough protein (generally 0.7-1g per pound of goal body weight) and resistance training preserves far more muscle mass during the loss phase, which is what actually determines how your body looks at the new weight and how easy the new weight is to maintain.
Activity Level Changes the Math More Than People Expect
Two people at the identical weight, height, age, and sex can have maintenance calories 500+ apart purely based on activity level. This is why simply “eating less” without accounting for how much you move is such an unreliable strategy — someone who added three weekly strength sessions and a daily walk without changing their food intake at all can end up in a deficit they didn’t plan for, or vice versa if activity dropped. Recalculating maintenance every 10-15 lbs of change (or with any big shift in exercise routine) keeps the deficit calculation honest.
Protein Needs Don’t Shrink When Calories Do
Protein is the nutrient most people under-eat while cutting calories, and it’s also the one most protective of muscle mass during a deficit. A practical target is 0.7-1 gram of protein per pound of goal body weight, spread across 3-4 meals rather than loaded into one. For a 150-lb goal weight, that’s roughly 105-150 grams daily — noticeably more than the general population’s typical intake. Hitting this number usually means prioritizing protein first when planning a meal (a palm-sized portion of lean meat, fish, eggs, dairy, or a plant-based equivalent like tofu or lentils) and building carbs and fat around it, rather than treating protein as an afterthought.
Fiber, Fullness, and Sticking to the Number
Calorie deficits fail more often from hunger-driven abandonment than from bad math. Fiber-rich foods — vegetables, legumes, whole grains, fruit with the skin on — take up more stomach volume and digest more slowly per calorie than refined carbs or added sugars, which makes a 1,800-calorie day built around whole foods feel considerably more satisfying than the same 1,800 calories built around processed snacks. A general target of 25-35 grams of fiber daily, combined with the protein range above, is one of the more reliable levers for making a deficit feel sustainable rather than like a countdown to the next meal.
Common Mistakes When Calculating Your Number
A few errors show up repeatedly:
- Using a generic “2,000 calorie” reference. That figure is a food-label convention, not a personal target — it happens to be roughly accurate for some people and far off for others depending on the variables above.
- Double-counting exercise calories. If your maintenance estimate already used an “active” multiplier, adding back the calories a workout watch says you burned that same day usually overshoots — the activity multiplier already accounts for a typical week of exercise.
- Recalculating too often. Adjusting the target daily based on the scale’s daily fluctuation (which is mostly water weight) leads to constant, unnecessary changes. Reassess every 2-3 weeks using the trend, not any single day’s number.
- Ignoring liquid calories. Coffee add-ins, juice, alcohol, and sweetened drinks are an easy place for 300-500 calories to hide from an otherwise careful count.
Tracking Without Obsessing
You don’t need to weigh every gram of food indefinitely to lose weight successfully. Tracking intake closely for 2-3 weeks is usually enough to learn realistic portion sizes and calorie density for your typical meals; after that, many people shift to “calibrated eyeballing” and only return to precise tracking if the scale stalls for more than 2-3 weeks. Daily Burn’s workout library pairs well with this approach — consistent training gives the scale-stall troubleshooting step (add activity vs. cut further) an easy first lever to pull before tightening food intake further. New members can try the full program risk-free, backed by a money-back guarantee, at $19.99/month.
Pairing the Right Deficit with the Right Training
The deficit size interacts with how hard you can train. A larger deficit (750-1,000 calories) tends to leave less energy for demanding workouts and slower recovery between sessions, which is one more reason the moderate 500-calorie range tends to outperform aggressive cuts over months rather than weeks — you can actually sustain the strength and interval training that protects muscle mass and keeps metabolism higher through the process. Pairing a moderate deficit with 2-3 resistance sessions and some interval or steady cardio each week is the combination most consistently linked to keeping lean mass while the scale moves down.
Frequently Asked Questions
How many calories should I eat to lose 1 pound a week?
Subtract roughly 500 calories from your maintenance number. One pound of fat is approximately 3,500 calories, so a 500-calorie daily deficit works out to about one pound of loss per week.
Is 1,200 calories too low?
For most adult women, 1,200 calories is close to the floor recommended without medical supervision, and for most adult men it’s generally too low. Going below the sustainable range risks inadequate nutrition and a metabolic slowdown that undermines further progress.
Do I need to eat fewer calories on rest days?
Not necessarily. Many people do fine eating a consistent calorie target every day; others prefer to shift calories slightly higher on training days and slightly lower on rest days. Either approach works as long as the weekly average matches your target deficit.
Why am I not losing weight even though I’m in a deficit?
The most common causes are underestimating portion sizes (a persistent issue even for careful trackers), water retention masking fat loss short-term, or a maintenance-calorie estimate that’s simply off for your actual metabolism. Give any deficit 2-3 weeks before adjusting, then recalibrate based on real results rather than the formula alone.
Does exercise let me eat more and still lose weight?
Yes, in the sense that exercise raises your total maintenance calories, which widens the gap you can eat into while still running a deficit. It’s not a free pass to eat back every calorie burned, since exercise calorie estimates (from watches, machines, or apps) tend to run high.
Is it better to eat fewer carbs or fewer calories overall to lose weight?
Total calorie deficit is what drives weight loss; macronutrient split (carbs vs. fat) mainly affects hunger, energy, and adherence rather than the fat-loss rate itself at a matched calorie level. Choose the split you can sustain longest.
How long should I stay in a calorie deficit?
Most guidance suggests periodic breaks — roughly 1-2 weeks at maintenance calories after every 8-12 weeks of dieting — to support recovery, hormone regulation, and long-term adherence, rather than staying in a deficit indefinitely.