🔥 Calorie / TDEE Calculator
Mifflin-St Jeor BMR and daily energy estimate. Runs privately in your browser.
From resting burn to daily burn
The calculation happens in two steps. First it computes your Basal Metabolic Rate (BMR): the energy your body burns at complete rest, driven by weight, height, age and sex. Mifflin-St Jeor is the equation most widely used because it tracks measured values reasonably well for most adults. Then it multiplies BMR by an activity factor, from sedentary (×1.2) to very active (×1.725+), to estimate total daily burn.
Because both steps are estimates, the output is a range, not a prescription. Metabolic adaptation, body composition and genetics move real requirements by 10% or more in either direction. Use the number as a starting budget, track your weight trend for two to three weeks, and adjust — that feedback loop beats any formula.
Mifflin-St Jeor and the activity multipliers
Mifflin-St Jeor BMR: men — 10 × kg + 6.25 × cm − 5 × age + 5; women — 10 × weight + 6.25 × height − 5 × age − 161. TDEE = BMR × activity multiplier (1.2 sedentary, 1.375 light, 1.55 moderate, 1.725 very active).
A 35-year-old woman, lightly active
A 35-year-old woman, 165 cm, 70 kg, lightly active (×1.375): BMR = 10×70 + 6.25×165 − 5×35 − 161 = 1,395. TDEE ≈ 1,918 kcal/day. To lose roughly half a kilo a week she would target about 1,400–1,450 kcal; to gain, 2,200–2,400. The calculator also shows an illustrative 40/30/30 carb/protein/fat split as a starting macro frame.
The activity-multiplier trap
- Overestimating activity level. Most people should pick one level below their self-assessment; a desk job with three gym sessions is 'lightly active', not 'very active'.
- Eating back exercise calories in full — fitness trackers routinely overcount burn.
- Cutting too aggressively. Eating far below BMR stalls adherence; 300–500 kcal below TDEE is the sustainable zone for most.
- Forgetting that TDEE falls as you lose weight. Recalculate every 5 kg of change.
Calorie questions
What is the difference between BMR and TDEE?
BMR is your burn at total rest; TDEE adds daily movement and exercise on top. Diets should be planned against TDEE, never below BMR for extended periods.
Which activity multiplier should I pick?
Be honest about non-exercise movement too. Office job + 3 gym sessions a week ≈ light-to-moderate (1.375–1.55). Construction work is genuinely 'active'.
How accurate is Mifflin-St Jeor?
Within about 10% for most adults — better than older equations like Harris-Benedict, but still an estimate.
Should I eat back calories burned in workouts?
Only partially, if at all. Most trackers overestimate; eating back half is a common compromise.
Is the macro split personalised?
The 40/30/30 split shown is an illustrative default, not a recommendation. Protein needs in particular scale with activity and goals.
Other health tools
Tip: double-check inputs before relying on results for important decisions.