2026-04-17 · how many calories, calorie deficit, weight loss calculator, TDEE, Mifflin-St Jeor, calorie tracking, nutrition, beginner

Updated 2026-07-29

How many calories should I eat to lose 1 pound per week?

For most adults, a 500 kcal/day deficit from your maintenance intake is the classic target for losing about 1 pound per week — the number comes from the old '3,500 kcal per pound' rule of thumb. That usually lands women in the 1,400 to 1,700 kcal/day range and men in the 1,700 to 2,000 kcal/day range, depending on body size and activity. Hall 2011 in *The Lancet* showed the 3,500-kcal rule overestimates long-term loss by roughly 50% because energy expenditure falls as you shrink, so expect the initial 1 lb/week to slow to closer to 0.5 lb/week after the first several months without a further adjustment.

How many calories to lose 2 pounds a week — is that safe?

A 1,000 kcal/day deficit targets roughly 2 lb/week and is only appropriate for adults with substantial weight to lose — clinical guidelines generally cap safe rates at 0.5 to 1% of body weight per week to protect lean mass. For a 250 lb adult that upper bound is about 2.5 lb/week; for a 150 lb adult it is closer to 1 lb/week, and pushing beyond that raises the risk of muscle loss, gallstones, and adaptive slowdown. If your calculated target drops below 1,200 kcal (women) or 1,500 kcal (men) to hit 2 lb/week, do not go that low without a clinician — pair a smaller deficit with more movement instead.

What is the lowest calorie limit that is still safe?

Clinical guidance is that adults dieting without medical supervision should not go below roughly 1,200 kcal/day for women or 1,500 kcal/day for men. Below those floors it becomes very hard to meet protein and micronutrient needs from food, and the risk of muscle loss, nutrient gaps, gallstones, hair loss, cold intolerance, amenorrhea, and rebound overeating climbs sharply. Very low calorie diets (below 800 kcal/day) do exist as medically supervised interventions for specific patients — for example, meal-replacement programs before bariatric surgery — but they belong in a clinical setting with regular monitoring, not as a self-directed starting point.

How do I know my personal TDEE?

TDEE is your total daily energy expenditure — everything you burn in 24 hours, including resting metabolism, movement, and digestion. Estimate it in two steps: calculate BMR with the Mifflin-St Jeor equation (10 × weight in kg + 6.25 × height in cm − 5 × age + 5 for men, or − 161 for women), then multiply by an activity factor of 1.2 (sedentary), 1.375 (lightly active), 1.55 (moderately active), or 1.725 (very active). Rounded predictions carry a 10 to 20% error band, so refine the number by tracking your intake and 7-day rolling weight over 3 to 4 weeks — actual data always beats the equation.

Do I need to eat less on the days I don't exercise?

Not usually. Most people find it simpler and more sustainable to hit the same daily calorie target every day and let the weekly deficit average out — a 500 kcal/day deficit hit consistently across 7 days is easier to plan than a rotating target. The exception is if you added a genuinely new, high-volume exercise habit (marathon training, several strength-and-conditioning sessions per week) that materially changed your weekly expenditure — in that case, either bump your activity multiplier up one row and recalculate, or eat a portion of the added burn on training days. Do not eat back estimated calorie burns from wearables meal-by-meal; those readouts commonly overestimate by 20 to 50%.

Why am I not losing weight in a calorie deficit?

The single most common answer is that the deficit is smaller than you think — food-diary studies consistently show adults underestimate intake by 20 to 40%, especially cooking oils, drinks, condiments, and weekend meals. Before assuming your metabolism is broken, weigh portions with a kitchen scale for 7 to 10 days and log every bite and sip. Secondary causes include water retention from a new training block, hormonal cycles, high sodium, or steadily dropping NEAT (fidgeting, walking) as the diet drags on. See our [weight loss plateau](/weight-loss/weight-loss-plateau/) guide for the full diagnostic checklist that walks through the twelve most common causes in the order to check them.

Should I count calories forever?

No. Calorie tracking is a learning tool, not a permanent obligation. Most people benefit from 3 to 8 weeks of deliberate logging to build accurate portion intuition — learning what 4 oz of chicken, a tablespoon of olive oil, or a typical restaurant pasta portion actually contains. After that, many people transition to lighter methods: plate-composition rules (half vegetables, palm of protein, fist of starch), a rolling weekly weigh-in with adjustments if the trend drifts, or tracking only protein and letting the rest fall into place. The evidence supports periodic re-tracking during maintenance — not continuous tracking — as the best long-term pattern.

Do I have to track weekends too?

Yes, if you want the tracking data to be useful. The most common reason a weekday-only tracker stalls is that Friday-through-Sunday intake adds several hundred to a couple of thousand extra calories per week — alcohol, restaurant meals, snacks in front of a screen — that quietly cancel the Monday-through-Thursday deficit. If you cannot bear to log every weekend, at least log the two or three items that historically add the most calories (drinks, dessert, weekend brunch) so the weekly average reflects reality. Track the whole week for the first month; after that, spot-checks are usually enough.

How Many Calories Should I Eat to Lose Weight

Most adults lose weight eating 1,400 to 2,000 kcal per day, with a 300 to 500 kcal/day deficit below their maintenance intake producing roughly 0.5 to 1 lb of loss per week. Your personal number depends on height, weight, age, sex, and activity — this guide walks you through the calculation, shows what the evidence actually says about how fast weight comes off, and explains why cutting further than the numbers below usually backfires.

Quick stats

• 1,400–2,000 kcal/day — typical adult range for weight loss
• ~1,200 kcal (women) / ~1,500 kcal (men) — safe intake floors without a clinician
• ~500 kcal deficit ≈ 1 lb/week — classic rule of thumb (decays over months; Hall 2011)
• 0.5–1% body weight/week — evidence-based safe rate for protecting lean mass
• 10–15% body-weight loss maintained at 12 months — realistic outcome from structured programs (Look AHEAD; DIETFITS)

Key takeaways

• Most adults lose weight eating somewhere between 1,400 and 2,000 calories per day, depending on body size and activity level.
• A deficit of about 500 calories per day targets roughly 1 pound of weight loss per week — but this rate slows over months as your body adapts.
• Your number depends on height, weight, age, sex, and how much you move. Anchor it to your estimated TDEE, not to a fixed calorie band you saw on the internet.
• Going too low (below 1,200 kcal for women or 1,500 kcal for men without medical supervision) raises the risk of muscle loss, nutrient gaps, gallstones, and rebound overeating.
• Calorie tracking is a short-term learning tool, not a permanent lifestyle requirement — most people transition to lighter methods after 4 to 8 weeks.

Who this is for

This article is for beginners and intermediates who want a clear, actionable answer to “how many calories should I eat?” You may be starting a diet for the first time, downloading a calorie-tracking app, or just trying to understand what the numbers mean. If you have a history of eating disorders, a diagnosed metabolic condition, or are pregnant or breastfeeding, work with a clinician or registered dietitian to set your targets rather than following a generic calculator.

The short answer

Most adults will lose weight eating 1,400 to 2,000 calories per day, depending on body size and activity. But the right number is personal. Someone who is 5’2” and sedentary needs a very different intake than someone who is 6’1” and exercises five days a week. The rest of this guide shows you how to find yours. If you are not sure whether you need to lose weight in the first place, start with our BMI calculator to see your weight category and healthy-weight range, then come back here to set a target.

How to estimate your personal target

Finding your number takes four steps. Do them in order — most of the mistakes people make with calorie targets come from skipping step 2 or overshooting step 3.

Step 1 — Estimate your BMR. BMR (basal metabolic rate) is roughly what your body would burn if you spent the whole day in bed. The most-cited equation is Mifflin-St Jeor (Mifflin 1990 AJCN): 10 × weight kg + 6.25 × height cm − 5 × age + 5 for men, or − 161 for women. If you would rather not do arithmetic, the 14 to 16 kcal per pound of body weight shortcut lands within ~10% of Mifflin for adults of average build.

Step 2 — Multiply by an activity factor, then round down one row. Standard multipliers are 1.2 (sedentary), 1.375 (lightly active), 1.55 (moderately active), and 1.725 (very active). The catch is that self-reported activity consistently overestimates by roughly half a category — Wing & Hill’s National Weight Control Registry work and follow-on activity-tracker validation studies show most people classify themselves one row above their true bracket. Pick the description that fits and then move one row lower. This single adjustment prevents the most common “I did the math but I’m not losing” trap.

Step 3 — Subtract 300 to 500 kcal to target 0.5 to 1 lb/week. For adults with a large amount to lose (BMI ≥ 30 with clinician oversight), a 500 to 750 kcal/day deficit can be appropriate, but the deficit should not exceed roughly 25% of your TDEE. Deeper deficits accelerate muscle loss and adaptive thermogenesis without accelerating the outcome you actually care about — sustained loss (Ashtary-Larky 2020 meta-analysis of rate-of-loss trials; see our adaptive thermogenesis guide).

Step 4 — Set a protein floor of 1.6 g/kg body weight. Protein is the macronutrient that protects lean mass in a deficit, and it also increases satiety, which makes hitting the calorie target easier. Longland 2016 in AJCN showed 1.6 g/kg preserved dramatically more lean mass than the standard 0.8 g/kg RDA in a matched-calorie trial. See our protein intake for weight loss guide for gram targets and food sources across the day.

Setting the goal weight itself. The 5–10% loss target above is the evidence-supported starting point, but if you also want a longer-run target weight to work toward, use a range, not a single number. The healthy BMI band at your height (18.5–24.9 kg/m²) is the modern reference; a specific single-number “ideal body weight” from the older clinical formulas (Hamwi, Devine, Robinson, Miller) usually sits near the low end of that range and was designed for drug dosing, not weight-loss goal-setting. The ideal weight calculator puts all four historical formulas alongside the healthy BMI range at your exact height so you can see the whole picture in one place.

Example calculations

170 lb moderately active woman, age 35, 5’5”:

• Weight 77 kg. Height 165 cm.
• BMR: 10 × 77 + 6.25 × 165 − 5 × 35 − 161 ≈ 1,440 kcal.
• Activity: description “moderately active” (1.55) → round down to 1.375 → 1,440 × 1.375 ≈ 1,980 kcal TDEE.
• Target with 400 kcal deficit: ~1,580 kcal/day. Protein floor: 77 kg × 1.6 = ~125 g.

200 lb sedentary man, age 40, 5’10”:

• Weight 91 kg. Height 178 cm.
• BMR: 10 × 91 + 6.25 × 178 − 5 × 40 + 5 ≈ 1,828 kcal.
• Activity: “sedentary” (1.2) → cannot round lower → 1,828 × 1.2 ≈ 2,194 kcal TDEE.
• Target with 500 kcal deficit: ~1,694 kcal/day. Protein floor: 91 kg × 1.6 = ~145 g.

Both numbers are estimates with a ±10 to 20% error band. The point is a defensible starting point that you refine with 3 to 4 weeks of real intake data and a 7-day rolling weight trend. Want the arithmetic done for you? Our interactive TDEE and calorie-deficit calculator returns BMR, maintenance calories, and a beginner-safe target in one click.

Evidence at a glance

The claims in this article come from a small set of foundational trials and models. If you are checking a specific number, this table maps each claim back to its source.

Two through-lines matter. First, the deficit drives the loss — DIETFITS is the cleanest demonstration that at matched calories the macro split (carb vs fat) does not meaningfully change 12-month body-weight outcomes. Second, static deficits produce curved outcomes, not linear ones — Hall 2011 is the mathematical explanation for why “I lost weight for 3 months, then it stopped” happens even in people who kept the diet identical. A shrinking body burns fewer calories, so a fixed intake becomes a smaller deficit as loss accumulates.

Why going too low usually backfires

Cutting calories aggressively feels productive at first, but it creates problems that undermine long-term results.

Metabolic adaptation. When you eat well below your needs for an extended period, your body reduces non-exercise movement, lowers thyroid output, and burns fewer calories at rest — the effect is called adaptive thermogenesis. Fothergill 2016 in Obesity followed Biggest Loser contestants and found their measured RMR sat roughly 500 kcal/day below what body mass alone predicted, six years after the competition. Most non-crash-diet adults land in a smaller residual — 150 to 300 kcal/day below prediction — but the direction is the same. A moderate deficit paired with resistance training and a protein floor minimizes this effect. See our adaptive thermogenesis guide for the full mitigation stack, or the plateau troubleshooter if you are already stuck.

Muscle loss. In a large deficit, your body breaks down muscle tissue for energy — especially if protein intake is low. Losing muscle lowers your metabolic rate and makes it harder to keep weight off. Prioritizing protein intake and resistance training helps preserve lean mass.

Hunger and binge cycles. Very low calorie diets ramp up hunger hormones (ghrelin) and reduce satiety hormones (leptin). The result is intense cravings that often lead to overeating, followed by guilt and another round of restriction. This restrict-binge pattern is one of the most common reasons diets fail.

Nutrient deficiencies. Below 1,200 to 1,400 calories, it becomes very difficult to get adequate iron, calcium, B vitamins, and fiber from food alone. Deficiencies affect energy, mood, immune function, and bone health.

Gallstones. Rapid weight loss — especially rates faster than about 1.5 kg (3.3 lb) per week — increases the risk of gallstone formation because bile becomes supersaturated with cholesterol as the liver mobilizes fat stores. It is one of the reasons medically supervised very-low-calorie programs monitor for gallbladder symptoms and often add ursodeoxycholic acid.

Adherence collapse. The steepest cost is behavioural. Look AHEAD showed 8.6% average loss at 1 year at a ~500 kcal/day intended deficit — but the same trial’s dropout and adherence curves flatten fast when initial deficits are set too aggressively. A tolerable deficit you can hold for months beats a punishing one you abandon in six weeks.

The better approach is a moderate deficit (300 to 500 kcal/day below TDEE), adequate protein, and some physical activity — with a periodic recalculation of TDEE every 10 to 15 lb of loss to keep the deficit real.

Calorie ranges by size and activity

These ranges give you a rough map of where different adults land after step 1 to 3 above. They are starting points, not prescriptions — anchor your final number to your own TDEE, not to a row in this table.

If your calculated number falls near 1,200 (women) or 1,500 (men) and you do not have a clinician supervising, that is a signal to bump activity rather than trim further. Those two floors are the practical thresholds used across the AHA/ACC/TOS 2013, Endocrine Society 2016, and NIH NHLBI 1998 guidelines — you can see all three side-by-side on the weight-loss guidelines and numbers reference. A larger TDEE from more movement is almost always more sustainable than a smaller intake from more restriction — and it protects the lean mass that anchors your metabolic rate. See our how to increase TDEE guide for the durable levers.

Common mistakes

Even a defensible calorie target won’t produce results if the execution drifts. These are the five patterns that most often quietly cancel a deficit.

• Crash-dieting for a week, then bingeing on the weekend. A Monday-to-Thursday deficit of 3,000 kcal is easily erased by a Friday-to-Sunday surplus of 3,000+ kcal. Weekly average intake is what moves the scale; single days do not.
• Ignoring liquid calories. Juices, sweetened coffees, sodas, and — especially — alcohol are the largest hidden-calorie category for adults. A single margarita or IPA can carry 200 to 300 kcal, and a Friday-night pattern of three drinks × two weekend nights is 1,200 to 1,800 kcal per week that many trackers under-log.
• Tracking only weekdays. If you cannot bear to log every weekend, at least log the two or three items that historically add the most calories — drinks, dessert, brunch — so the weekly average reflects reality.
• Dropping calories again the moment the scale sticks. A 3-week flat trend is often a hydration or bowel-content artefact, not a stalled deficit. Look at the 7-day rolling average across 4 weeks, check portion accuracy, and only then consider trimming another 100 to 200 kcal.
• Tracking without weighing. Volumetric estimates (“one cup of rice”, “a tablespoon of peanut butter”) drift by 30 to 50% within the same person. A kitchen scale for the first 7 to 10 days calibrates your eye — after that, you can go back to estimating with much better accuracy.

When tracking becomes a problem

Calorie tracking is a useful tool for most adults and a harmful one for some. Watch for these warning signs and, if they show up, stop tracking and consider working with a registered dietitian or a therapist who specializes in disordered eating.

• Anxiety, guilt, or shame around eating tracked foods “wrong”.
• Avoiding social meals, restaurants, or shared food because the calorie content is uncertain.
• Compensating for a high-calorie meal with a punitive deficit or extra exercise the next day.
• Feeling unable to eat without logging first, even at maintenance or after reaching goal weight.
• Preoccupation with food purity, macros, or “clean eating” that crowds out other interests.
• History of anorexia, bulimia, binge eating disorder, or orthorexic patterns.

People with a history of disordered eating should discuss tracking with a professional before starting. Alternate approaches that work well without numeric tracking include a plate-composition rule (half vegetables, a palm of protein, a fist of starch), a protein-only tracking approach (hit the gram target and let calories fall into place), or a habit-based framework built on food quality and portion cues rather than logged numbers.

Sources at a glance

If you are verifying a specific claim in this article, this table maps each core number back to a primary source. The full citations are in the sources block at the bottom.

Practical next steps

This week:

• Estimate your TDEE using the Mifflin-St Jeor equation and the “round activity down one row” rule (or use our TDEE and calorie-deficit guide for a step-by-step walkthrough).
• Subtract 300 to 500 kcal to set a starting target. Make sure the result stays above 1,200 (women) or 1,500 (men) unless a clinician has cleared a lower number.
• Set a protein floor at 1.6 g/kg body weight and plan how you will hit it across 3 to 4 meals.
• Download a calorie-tracking app and log everything for 7 days, including cooking oils, drinks, and sauces. Use a kitchen scale for the first week to calibrate your portion eye.
• If your starting target lands in the 1,400 to 1,600 range — the most common starting bucket — copy our 1,500-calorie sample week for a worked example of per-meal portions and a grocery list. Landing higher on the ladder? Use the 1,800 or 2,000 calorie meal plan for active men in a moderate deficit or taller adults finishing a loss phase.

Over the next month:

• Track your 7-day average weight each week. Look for a downward trend of 0.5 to 1% of body weight per week.
• Aim for a protein target at each meal. See our protein intake guide for specific gram ranges and food sources.
• If the trend is flat for 3 or more weeks with consistent tracking, work through the plateau troubleshooter before cutting further — most stalls trace back to portion drift or a shrinking NEAT, not a broken metabolism.
• Turn your daily calorie target into a repeatable weekly menu — our guide on how to build a weight loss meal plan from scratch walks through the steps, or browse the full meal plans hub sorted by calorie band and dietary pattern.

What to watch for:

• Manageable hunger (not extreme or constant).
• Stable energy throughout the day.
• Gradual, consistent weight loss on the weekly average.
• Preserved training performance in the gym.
• If none of these are true after 3 to 4 weeks of consistent tracking, revisit your TDEE estimate and your portion accuracy before cutting further. If losing belly fat specifically is the goal, our how to lose belly fat guide covers why spot reduction is a myth and what the evidence actually supports.