Health & Fitness
Calorie Calculator
Find calorie targets, macros, and projected weight change for your goal.
Result
Enter your numbers and press Calculate to see the result.
Calculating…
How your daily calories are calculated
The calculator estimates your basal metabolic rate with the Mifflin-St Jeor equation, multiplies it by an activity factor to get your maintenance calories (TDEE), then applies the daily surplus or deficit you choose for your goal. It also suggests a macro split from your editable inputs: protein grams per kilogram, fat as a percentage of calories, and carbs filling the rest.
Formulas
Maintenance (TDEE) = BMR × activity factor
Daily target = TDEE + goal offset (kcal)
Protein = protein g/kg × weight (kg) · Fat = fat% of kcal ÷ 9 · Carbs = remaining kcal ÷ 4
Activity factors
| Lifestyle | Factor |
|---|---|
| Sedentary (little exercise) | 1.2 |
| Light activity (1–3 days/week) | 1.375 |
| Moderate (3–5 days/week) | 1.55 |
| Very active (6–7 days/week) | 1.725 |
| Extra active (physical job + training) | 1.9 |
Worked example
A 30-year-old woman, 70 kg, 170 cm, moderately active (1.55): BMR ≈ 1,452 kcal, so maintenance ≈ 1,452 × 1.55 = ≈ 2,250 kcal/day. With a 500 kcal deficit the daily target is ≈ 1,750 kcal — roughly 0.45 kg (1 lb) of weight loss per week. With the default 1.8 g/kg protein and 25% fat inputs, macros are about 126 g protein, 49 g fat, and 202 g carbs.
Choosing a safe deficit or surplus
Roughly 7,700 kcal equals one kilogram of body fat (about 3,500 kcal per pound), which is why a 500 kcal daily deficit trends toward about 0.45 kg (1 lb) of loss per week. A deficit of 500–750 kcal is a common, sustainable range; cutting far more can cost muscle and is hard to maintain. For gaining, a modest surplus of 250–500 kcal supports lean growth with less fat than an aggressive bulk. Keeping protein high in either case helps preserve muscle.
Why the number is a starting point
Every equation is a population average, and activity factors are broad buckets — real metabolism varies with genetics, NEAT (fidgeting and daily movement), sleep, and how much muscle you carry. Treat the target as a two-to-four-week experiment: track your intake and weight, and if the trend is not moving as expected, adjust by 100–200 kcal rather than assuming the formula is exact.
These figures are estimates, not medical advice. See your resting burn in detail with the BMR calculator or check your weight category with the BMI calculator.
Calorie Calculator — frequently asked questions
How are my daily calories calculated?
Your BMR is estimated with the Mifflin-St Jeor equation, multiplied by an activity factor from 1.2 (sedentary) to 1.9 (very active) to get maintenance calories, then adjusted by the daily surplus or deficit you choose.
How large a deficit do I need to lose weight?
A deficit of about 500 kcal per day corresponds to roughly 0.45 kg (1 lb) of body weight per week. Moderate deficits are easier to sustain and preserve more muscle than aggressive ones.
How is the macro split calculated?
Protein uses the grams-per-kilogram value you enter (1.8 g/kg by default), fat uses the percent of calories you enter (25% by default), and carbohydrates fill the remaining calories. Protein and carbs count 4 kcal/g; fat counts 9 kcal/g.
Should I ever eat below my BMR?
Very low intakes are hard to sustain and can miss essential nutrients. These figures are general estimates, not medical advice — consult a doctor or registered dietitian before starting an aggressive diet.