Calorie calculator — how many calories you need a day
Knowing your daily calorie target is the starting point for any nutrition plan. This calculator estimates the calories you burn in a typical day — your maintenance level — using the well-regarded Mifflin–St Jeor equation, and then suggests targets for losing or gaining weight at a sustainable pace.
How it works
First the tool estimates your basal metabolic rate (BMR) — the energy your body
uses at rest — with the Mifflin–St Jeor equation:
BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + s, where s is +5 for men
and −161 for women. It then multiplies BMR by an activity factor (1.2 sedentary
up to 1.9 very active) to give your total daily energy expenditure, which is your
maintenance calories.
Worked example
A 30-year-old woman, 168 cm, 65 kg, moderately active:
BMR = 10 × 65 + 6.25 × 168 − 5 × 30 − 161 = 1,389 kcal- Maintenance at the moderate factor 1.55:
1,389 × 1.55 ≈ 2,153 kcal/day - Steady loss (−500): about 1,653 kcal/day
Practical tips
Be honest about activity. Most people overestimate how active they are. If you train hard three days a week but sit the rest, “light” or “moderate” is usually closer than “active”.
Adjust from results, not theory. Use the estimate as a two-week starting point, track your weight trend, and nudge the target up or down based on what actually happens — real data beats any formula.
Do not go too low. Very aggressive deficits are hard to sustain and can cost you muscle. A mild-to-moderate deficit paired with protein and resistance training is usually more effective long term.
These figures are estimates for general fitness planning, not medical advice. All calculations run entirely in your browser — nothing is uploaded or stored.