Calorie Calculator

Find your BMR and daily calorie needs in seconds. Enter your age, gender, height, weight and activity level — get your maintenance calories plus targets for losing weight, staying the same or gaining muscle. Everything runs in your browser; no signup, no data leaves your device.

By UpnixTools · Calculator and figures last reviewed November 2026

Your Details

Be honest — most people overestimate their activity. If you sit most of the day, choose Sedentary or Lightly active.

Your Daily Calories

Maintenance calories (TDEE)
—
BMR: —
BMR (at rest)—
Activity factor1.55×
Lose weight
—
TDEE − 500 kcal
~0.5 kg / week
Maintain
—
Eat your TDEE
weight stays stable
Gain muscle
—
TDEE + 500 kcal
with strength training

Suggested macros at maintenance

Protein · 30%— g / day
Carbs · 40%— g / day
Fat · 30%— g / day

Estimates only — the Mifflin-St Jeor equation is accurate to about ±10% for most people. Track your weight for 2–3 weeks and adjust by 100–200 calories based on real results.

How the calorie calculator works

This calculator uses the Mifflin-St Jeor equation — the formula most dietitians consider the most accurate for estimating BMR in the general population:

Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161

Your BMR is then multiplied by an activity factor (1.2 for sedentary up to 1.9 for extra active) to get your TDEE — the total calories you burn per day. From there the targets are simple: subtract about 500 calories a day to lose roughly 0.5 kg per week, or add about 500 to gain weight (best paired with strength training so the gain is mostly muscle).

How to use your numbers

Calorie Calculator FAQs

What is BMR?
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest, just to keep you alive — breathing, circulation, body temperature and basic cell functions. For most adults it is 60–75% of all calories burned in a day. This calculator estimates BMR with the Mifflin-St Jeor equation, the formula most dietitians consider the most accurate for the general population.
How many calories should I eat to lose weight?
A common, sustainable target is about 500 calories below your maintenance level (TDEE), which typically leads to roughly 0.5 kg (1 lb) of fat loss per week. Faster loss is possible but harder to sustain and raises the risk of muscle loss. Avoid going below your BMR for long periods without medical supervision.
What is TDEE?
TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor — it estimates all the calories you burn in a day, including movement, exercise and digestion. If you eat your TDEE, your weight stays roughly stable; eat below it and you lose weight; eat above it and you gain.
How accurate is this calorie calculator?
The Mifflin-St Jeor equation is accurate to within about 10% for most people, but individual results vary with muscle mass, genetics and daily activity. Treat the number as a starting point: track your weight for 2–3 weeks, then adjust your intake up or down by 100–200 calories based on what the scale actually does.
Should I ever eat fewer calories than my BMR?
Generally no. Your BMR is the minimum your body needs at rest, and eating far below it for weeks can cause fatigue, muscle loss and hormonal problems. A safe deficit is usually 300–500 calories below your TDEE, not below your BMR. If your TDEE is close to your BMR, talk to a doctor or dietitian before dieting.

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