Free Calorie Calculator (TDEE)

Estimate daily calorie needs using the Mifflin-St Jeor equation. Includes BMR, TDEE, and target calories for weight loss or gain.

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What is this calculator for?

You decided this morning that you're going to actually lose 20 pounds this year, and you Googled "how many calories should I eat" and got answers ranging from 1,200 to 2,800. The variance is because everyone needs a different number — based on age, sex, height, weight, and activity level. The calorie calculator gives you the specific maintenance number for your body plus the deficit needed for weight loss at sustainable rates.

Caloric needs follow a roughly predictable formula. Your basal metabolic rate (BMR) is the energy your body burns at rest — about 60-70% of total daily calorie burn for most people. Activity adds 15-30% on top depending on how much you move. Thermic effect of food (calories burned digesting) adds 5-10%. Total daily energy expenditure (TDEE) is BMR × activity multiplier.

The Mifflin-St Jeor formula is the most widely-used BMR equation, validated against measured metabolic rates in thousands of subjects: For men: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age + 5. For women: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age - 161. Activity multipliers: sedentary (×1.2), lightly active (×1.375), moderately active (×1.55), very active (×1.725), extremely active (×1.9). Most office workers with moderate exercise routines are 1.375-1.55.

This calculator gives you BMR, TDEE, and target calorie intake for: maintain weight, lose 0.5/1/2 lbs per week, gain 0.5/1 lb per week. The deficits assume 3,500 calories per pound of body weight (a simplification, but reasonable for short-term planning).

How to use this calculator

Enter age, sex, height (in inches or cm), and weight (in lbs or kg). The Mifflin-St Jeor formula uses these four inputs to compute BMR — the calorie floor your body burns even if you stayed in bed all day.

Select your activity level. Sedentary (×1.2): desk job, almost no exercise. Lightly active (×1.375): desk job + 1-2 light workouts per week. Moderately active (×1.55): desk job + 3-4 moderate workouts per week, or active job (retail, teaching, etc.). Very active (×1.725): physical job + regular workouts, or 5-6 intense workouts per week. Extremely active (×1.9): elite athlete with 2-a-day training, manual laborer, military training. Most people overestimate their activity level — if you sit at a desk 8-10 hours and do three 45-minute gym sessions per week, you're moderately active at most.

Choose your goal: maintain weight, lose weight (0.5/1/2 lbs per week), or gain weight (0.5/1 lb per week). The calculator subtracts (or adds) calories from your TDEE based on the goal. Sustainable weight loss: 0.5-1 lb/week. Aggressive but still sustainable for short bursts (3-6 months): 1.5-2 lbs/week. Above 2 lbs/week consistently is extreme; muscle loss and metabolic adaptation become significant problems.

The calculator outputs BMR, TDEE, and recommended daily calorie intake for your chosen goal.

Understanding your results

The calculator returns your BMR (the floor — what you'd burn just being alive), TDEE (what you actually burn each day with activity), and target intake for your goal.

How to read it. A 35-year-old man, 5'10", 195 lbs, lightly active: BMR ≈ 1,830 cal. TDEE ≈ 2,517 cal. To lose 1 lb/week (500 cal deficit): eat 2,017 cal. To lose 0.5 lb/week (250 cal deficit): eat 2,267 cal. The half-pound-per-week rate is much easier to sustain long-term and rarely triggers metabolic adaptation; the 1-lb rate is the standard "aggressive but sustainable" target.

The 3,500-calorie rule. The traditional formula: 3,500 calories = 1 pound of body fat. So a 500-calorie daily deficit (sustained) produces 1 pound of loss per week. The reality is more complex — your body adapts, basal metabolism declines slightly as weight drops, water weight fluctuates, and not all weight loss is fat. The 3,500 rule overestimates loss for long-term sustained deficits (real loss is typically 70-85% of predicted). For short-term planning (1-3 months), the rule is reasonable. For 6-12 month projections, expect to need slightly larger deficits or accept slightly slower progress than the math suggests.

The protein constraint. Calorie targets are necessary but not sufficient for body composition. Eating 1,800 calories of mostly Skittles produces very different results than eating 1,800 calories with 150g protein, balanced fats, and complex carbs. Protein intake should be 0.7-1.0 g per pound of target body weight for most people — this preserves muscle during a deficit and supports satiety. A 195-lb man targeting 180 lb should eat 130-180g protein per day. The Mubboo Macro Calculator handles the macronutrient breakdown after the calorie target is set.

The metabolic adaptation issue. Long deficits (6+ months) trigger metabolic adaptation — basal metabolism drops by 5-15% beyond what weight change alone would predict. This is why initial weight loss is faster than late-stage weight loss for the same calorie target. Working solutions: occasional "diet breaks" (1-2 weeks at maintenance every 8-12 weeks of deficit), gradual deficits rather than aggressive crashes, and tracking actual progress against predicted to adjust the target as needed.

A worked example

Maria, 42, 5'4" (163 cm), 178 lbs (81 kg), works as a nurse on her feet 12-hour shifts 3-4 days a week, no other formal exercise. She wants to lose 30 lbs in roughly a year — getting to 148 lbs by next April.

BMR (Mifflin-St Jeor, women): 10×81 + 6.25×163 − 5×42 − 161 = 810 + 1019 − 210 − 161 = 1,458 calories. Activity multiplier: moderately active (×1.55) reflects her on-feet work plus typical daily activity. TDEE: 1,458 × 1.55 = 2,260 calories.

To lose 30 lbs in 52 weeks: 0.58 lbs per week, or ~300 cal/day deficit. Target intake: 2,260 − 300 = 1,960 calories per day. Sustainable rate; she shouldn't feel hungry at this deficit.

Now Maria's reality after 4 months at 1,960 cal/day. She's lost 11 lbs (down to 167 lbs), which is on track. But weight loss has slowed — the last month saw only 1.5 lbs lost despite consistent eating. Her new TDEE at 167 lbs: roughly 2,170 cal. Same 300-cal deficit now means 1,870 cal/day target. Plus metabolic adaptation (8-10% reduction): real effective target may be 1,750-1,800 cal/day to continue losing 1 lb every 1.5 weeks.

One year later: Maria reaches 152 lbs (just shy of her 148 goal, but close — and she's added 30-minute resistance training 3x/week which has built some muscle). Her new TDEE at 152 lbs is 2,000 cal. She wants to maintain. She gradually increases intake to 2,000 cal/day, monitors weekly weigh-ins for 8 weeks. Weight stays stable. Her maintenance is established. The progression from active weight loss to maintenance is the hardest psychological transition — most people who fall back into old patterns do so in the first 2-3 months after hitting goal weight. The discipline of weekly weigh-ins and re-establishing maintenance intake mathematically and behaviorally is the difference between yo-yo weight cycling and sustained loss.

Related resources

For your maintenance calorie number and detailed activity-multiplier discussion, see TDEE Calculator. For the macronutrient breakdown after setting calories, the Macro Calculator. For body composition context beyond weight, the BMI Calculator and Body Fat Calculator. The CDC Healthy Weight portal publishes evidence-based weight management guidance and lifestyle research.

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Frequently asked questions

What does TDEE mean?

TDEE is Total Daily Energy Expenditure — the calories your body burns in a day including basal metabolism, daily activity, and exercise. Eating at TDEE maintains your current weight.

Why does this use the Mifflin-St Jeor equation?

Mifflin-St Jeor (1990) is the most accurate BMR formula for the general adult population according to peer-reviewed comparisons. It is the standard used by registered dietitians.

Why 500 calories for one pound per week?

One pound of body fat stores roughly 3,500 calories. A 500-calorie daily deficit times 7 days equals 3,500, producing approximately one pound of fat loss per week. Actual results vary by individual.

What's the difference between BMR and TDEE?

BMR (Basal Metabolic Rate) is what your body burns at complete rest — to power organs, maintain temperature, run basic cellular processes. Roughly 60-70% of total calorie burn for most people. TDEE (Total Daily Energy Expenditure) is BMR plus the calories burned by activity (NEAT — non-exercise activity thermogenesis — like fidgeting and standing, plus exercise activity thermogenesis from formal workouts) plus the thermic effect of food (10% of calories burned digesting). TDEE is what you need to eat to maintain weight; eating below TDEE = weight loss; above = weight gain. BMR is a number you don't directly eat against — it's just a component of TDEE.

Is calorie counting accurate?

Calorie counts on food labels have ±20% legal tolerance and many real-world meals deviate that much. Restaurant calorie counts can be off by 30-50%. Personal logging via MyFitnessPal underestimates intake by 10-30% (people forget about cooking oil, butter, drinks, snacking). So 'I ate 1,800 calories today' in practice might be 1,500-2,400. The math works if you're consistent — even if your tracked '1,800' is actually 2,100, the relationship between tracked intake and weight change is consistent. People who hit weight loss plateaus usually need to either tighten tracking (weigh foods, log oils, etc.) or accept that their tracked number underrepresents actual intake and adjust downward by 100-300 cal.

Should I eat the same calories every day or use weekly averaging?

Weekly averaging is more sustainable. Most successful long-term dieters target a weekly calorie total (e.g., 14,000 cal/week at 2,000 cal/day average) but accept day-to-day variance — eating 1,500 on a busy weekday and 2,500 on a social Saturday averages the same as 2,000 every day. Weekly averaging accommodates real life (work dinners, weekends, holidays) without breaking the deficit. The risk: 'weekend overshoot' that consumes the entire deficit. Tracking weekly totals and capping the weekend overshoot at 700-1,000 cal beyond weekday average keeps progress on track.

Why is my weight loss slowing down even though I'm eating the same?

Two factors. (1) You weigh less now, so your TDEE has dropped. A 50-pound loss reduces TDEE by roughly 250-400 cal/day depending on starting weight. The same 1,800 cal/day that was a 500-cal deficit at month one might be only a 200-cal deficit by month six. (2) Metabolic adaptation — your body downregulates basal metabolism somewhat as a survival response to sustained deficit, beyond what weight change alone explains. The combined effect: a plateau usually means your current intake matches your current TDEE; you need a smaller deficit applied to a smaller TDEE. Reset by recalculating TDEE at your current weight and choosing a fresh deficit; don't just eat less of the original plan.

Are there foods that boost metabolism significantly?

Not as much as marketing claims. Protein has the highest thermic effect (20-30% of calories burned digesting, vs 5-10% for carbs and 0-3% for fats), so a high-protein diet does increase TDEE marginally (50-100 cal/day depending on intake). Capsaicin (spicy food), green tea (catechins), caffeine, and very-cold-water consumption have measurable but tiny effects — usually 30-100 cal/day combined. The headline 'this superfood boosts metabolism' claims rarely survive controlled trials. The largest sustainable lever for increasing TDEE is increasing muscle mass via resistance training — each pound of muscle adds 5-7 cal/day to BMR. 10 lbs of added muscle = 50-70 extra cal/day burned at rest. That's why long-term physique transformations always include resistance training, not just calorie restriction.

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