Estimate how many calories your body needs per day. This calculator uses the Mifflin-St Jeor equation to find your Basal Metabolic Rate (BMR), then applies your activity level to estimate Total Daily Energy Expenditure (TDEE) — the calorie intake that would maintain your current weight.
Your Basal Metabolic Rate (BMR) of 1,649 kcal/day is an estimate of the energy your body needs at complete rest, just to keep basic functions like breathing and circulation running.
Your estimated daily needs (TDEE) of 2,556 kcal/day add your activity level (Moderate activity (3-5 days/week)) on top of that baseline — this is roughly the calorie intake that would maintain your current weight.
TDEE = BMR × activity multiplier.
This calculator provides general informational estimates and is not a medical diagnosis. Results should be interpreted alongside other factors. If you have concerns about your health, consider speaking with a qualified healthcare professional.
Your total daily calorie needs — formally called Total Daily Energy Expenditure (TDEE) — combine your Basal Metabolic Rate (calories burned at rest) with the energy used for daily activity, exercise, and digesting food. This total is the baseline for weight maintenance, and the starting point for any weight loss or gain plan.
| Activity level | Description | Multiplier |
|---|---|---|
| Sedentary | Desk job, little exercise | 1.2 |
| Light | Light exercise 1–3 days/week | 1.375 |
| Moderate | Moderate exercise 3–5 days/week | 1.55 |
| Active | Hard exercise 6–7 days/week | 1.725 |
| Very active | Physical job or 2x/day training | 1.9 |
Weight change is governed by energy balance: eating more calories than you burn leads to weight gain, eating fewer leads to weight loss. A commonly cited approximation is that roughly 3,500 calories corresponds to about one pound of body weight, though real-world results vary by individual and over time.
Example 1 — Maintenance: A 28-year-old man, 82 kg, 178 cm, moderately active: BMR = 10(82) + 6.25(178) − 5(28) + 5 = 820 + 1,112.5 − 140 + 5 = 1,797.5. TDEE = 1,797.5 × 1.55 ≈ 2,786 kcal/day to maintain weight.
Example 2 — Weight-loss target: Using the same TDEE of 2,786 kcal/day, a moderate 500-calorie deficit gives a daily target of about 2,286 kcal/day, aiming for roughly 1 lb (0.45 kg) of loss per week.
Example 3 — Sedentary vs. active comparison: A 35-year-old woman, 68 kg, 165 cm has a BMR of about 1,398 kcal/day. Sedentary, her TDEE is roughly 1,678 kcal/day; very active, it rises to about 2,656 kcal/day — nearly a 1,000-calorie difference from activity level alone.
| Daily deficit | Approx. weekly loss | Pace |
|---|---|---|
| 250 kcal | ~0.25 kg (0.5 lb) | Slow, easier to sustain |
| 500 kcal | ~0.45 kg (1 lb) | Moderate, common target |
| 750 kcal | ~0.7 kg (1.5 lb) | Aggressive |
| 1,000 kcal | ~0.9 kg (2 lb) | Very aggressive, harder to sustain |
Can I use this as an online calculator for weight loss? Yes — enter your stats and activity level, then subtract 500 calories/day from your maintenance number for a safe ~1 lb/week weight loss target.
How do I use this as a calorie tracker to gain weight? For weight gain, add 300–500 calories/day above your maintenance number shown here, and prioritize protein intake to support muscle growth rather than fat gain alone.
Why am I not losing weight at my calculated deficit? Estimation formulas carry margin of error, and factors like water retention, inconsistent tracking, or metabolic adaptation can all affect real-world results.
Is the 3,500-calorie-per-pound rule accurate? It's a useful rough approximation, but actual weight change also depends on changes in water, glycogen, and metabolic adaptation over time.
Should I eat back calories burned from exercise? Most activity multipliers already estimate typical exercise; eating back a portion of intense extra exercise calories can help avoid an overly large deficit.
What's the difference between BMR and TDEE again? BMR is calories burned at complete rest; TDEE adds daily movement, exercise, and digestion on top, giving your true total daily calorie need.
How large a deficit is safe for weight loss? A moderate deficit of 500–750 calories/day is commonly used for steady loss without excessive muscle loss or metabolic slowdown, though very low intakes should generally be supervised.
Do I need to recalculate as I lose weight? Yes — both BMR and TDEE fall as body weight decreases, so recalculating every 5–10 lbs (or every few weeks) keeps the target accurate.
Does this calculator account for pregnancy or breastfeeding? No — those states significantly increase calorie needs and should be assessed with a healthcare provider rather than a general TDEE formula.
Why do two calorie calculators give me different numbers? Different tools may use different formulas (Mifflin-St Jeor vs. Harris-Benedict vs. Katch-McArdle) or activity multipliers, which produces modest differences in the final estimate.
A 35-year-old woman, 165 cm, 65 kg, with a lightly active lifestyle has an estimated BMR around 1,400 calories, and a TDEE (including activity) of roughly 1,930 calories per day to maintain her current weight.
BMR: Basal Metabolic Rate — calories burned at complete rest.
TDEE: Total Daily Energy Expenditure — BMR plus activity, representing total daily calorie needs.
Calorie deficit: Consuming fewer calories than you burn, generally required for weight loss.
Calorie surplus: Consuming more calories than you burn, generally required for weight/muscle gain.
Why is my BMR different from my friend's at the same weight?
BMR depends on age, sex, and height as well as weight — body composition (muscle vs. fat) also plays a role that formulas can't fully capture.