BMR & TDEE Calculator
How it worksEstimate resting burn and daily calorie maintenance
Free BMR and TDEE calculator using the Mifflin–St Jeor equation. Estimate basal metabolic rate and total daily energy expenditure from age, sex, height, weight, and activity level.
Your details
Using: 70.0 kg · 175 cm
Your BMR & TDEE
BMR
1,649 kcal/day
TDEE (maintenance)
2,556 kcal/day
Daily energy breakdown
Example calorie targets
Rough deficit ideas: −250 kcal/day ≈ mild loss · −500 kcal/day ≈ ~0.5 kg/week trend for many adults (results vary).
About this BMR & TDEE calculator
Basal metabolic rate (BMR) estimates how many calories your body would use at complete rest. Total daily energy expenditure (TDEE) scales that estimate by how active you are across the whole day.
We use the Mifflin–St Jeor equation — a widely cited formula for estimating adult BMR from sex, age, height, and weight — then multiply by a standard activity factor.
These numbers are planning tools for nutrition targets, not lab measurements. Wearables, NEAT (fidgeting, walking), and individual hormones can shift real-world needs.
A BMR and TDEE calculator answers the question behind most calorie plans: roughly how much do I burn at rest, and across a normal day? Habbeat uses Mifflin–St Jeor plus standard activity multipliers so you can set maintenance, cut, or surplus targets with eyes open.
Queries like “TDEE calculator,” “maintenance calories,” and “Mifflin St Jeor” map directly to this tool. We show both BMR and TDEE so you see the difference between resting burn and full-day expenditure.
Pair calorie targets with Habbeat’s food logging and daily score — the number on this page is a plan, not a verdict.
How to use this free tool
- Enter sex, age, weight, height, and a realistic activity level that reflects your whole week — not only gym days.
- BMR is calculated with Mifflin–St Jeor. TDEE = BMR × activity multiplier (sedentary through very active).
- A mild calorie deficit relative to TDEE is often used for gradual fat loss; a surplus may support muscle gain when paired with training and protein.
Worked examples
- Example: A 30-year-old woman, 65 kg, 165 cm, lightly active might land near ~1,400 kcal BMR and ~1,900–2,000 kcal TDEE (order-of-magnitude only).
- Example: Raising activity from sedentary to moderately active often adds several hundred kcal to estimated TDEE — don’t invent “athlete” if your week is desk-heavy.
- Example: A 300 kcal daily deficit vs TDEE is a common starting point for gradual fat loss when food quality and protein are in place.
Practical tips
- If weight is stuck after 2–3 weeks, adjust calories by ~100–200 kcal rather than making huge swings.
- Pick the activity level that matches average movement; overestimating activity is a common source of stalled fat loss.
- Track body weight as a weekly average — daily water and glycogen noise is normal.
Limitations & caveats
- Mifflin–St Jeor is an estimate, not a metabolic lab test.
- NEAT, hormones, medications, and sleep can shift real needs.
- Aggressive deficits can hurt training and adherence — personalise carefully.
Frequently asked questions
What is the difference between BMR and TDEE?
BMR is an estimate of calories used at rest. TDEE adds movement, exercise, and daily living so you can plan maintenance, loss, or gain calories.
Which formula does Habbeat use?
Mifflin–St Jeor for BMR, then standard Harris–Benedict–style activity multipliers for TDEE. Other formulas (Harris–Benedict, Katch–McArdle) can differ slightly.
How big should a deficit be?
Many adults start around −250 to −500 kcal/day below TDEE for a gradual pace. Aggressive deficits are harder to sustain and can hurt training. Personalise with a professional if needed.
How accurate is a TDEE calculator?
Expect a useful starting band, not precision to the calorie. Adjust based on 2–3 week average weight change and energy in training.
Should I eat at BMR to lose fat?
Usually no. Eating near BMR for long periods is an aggressive deficit. Most adults plan from TDEE with a moderate gap instead.
Does muscle raise BMR?
Lean mass contributes to resting burn, but equations based only on weight/height/age won’t fully capture that. Strength training still helps body composition even when the calculator doesn’t “see” muscle.
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All toolsDisclaimer: These tools provide general estimates only. They are not medical advice. For health conditions, pregnancy, or personalised nutrition, speak with a qualified professional.