Calorie calculator (TDEE and macros)

Your daily calorie need is your BMR (the energy your body burns at rest) multiplied by an activity factor. That gives your maintenance calories, or TDEE. To lose fat, eat 10 to 20% below that number; to gain, eat 10 to 15% above it. For a moderately active 28-year-old man at 170 cm and 72 kg, maintenance is about 2,550 kcal a day and a sensible fat-loss target is about 2,040.

How the calculator works

There are three steps.

1. BMR. By default the calculator uses the Mifflin-St Jeor equation (Mifflin et al., American Journal of Clinical Nutrition, 1990):

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

A systematic review by the American Dietetic Association found it was the most reliable of the common formulas, predicting resting energy within 10% of the measured value in more people than the others.

If you know your body fat percentage, the calculator switches to Katch-McArdle, which works from lean mass instead of total weight: BMR = 370 + 21.6 × lean body mass (kg). It's better for people who are very muscular or carry a lot of fat, because Mifflin-St Jeor assumes average body composition. Only use it if your body fat number is reasonably good. A tape-measure estimate from the body fat calculator is fine; a bathroom scale's reading often isn't.

2. Activity. BMR is multiplied by a factor: 1.2 sedentary, 1.375 lightly active, 1.55 moderately active, 1.725 very active, 1.9 for athletes. Most people with a desk job who train 3 to 4 times a week sit closer to 1.375 or 1.55 than they think. If in doubt, pick the lower one.

3. Goal. The target is maintenance minus 20% (lose), minus 10% (lose slowly), plus 10% (lean gain) or plus 15% (gain). The weekly change uses the common estimate that about 7,700 kcal equals 1 kg of body fat. That figure is a simplification: Hall's work on weight-change dynamics shows weight loss slows over months as your body gets smaller and adapts, so treat the weekly figure as a guide for the first couple of months.

Worked example

A 28-year-old man, 170 cm, 72 kg, gym 4 days a week:

• BMR = 720 + 1,062.5 − 140 + 5 = 1,648 kcal
• Maintenance = 1,648 × 1.55 = 2,554 kcal
• Fat-loss target (−20%) = 2,043 kcal, a gap of about 510 kcal a day, or roughly 0.46 kg a week
• Protein 2.0 g/kg = 144 g, fat 25% = 57 g, carbs make up the rest = 239 g

How the macros are set

The protein numbers sit inside the range the International Society of Sports Nutrition gives for people who train (1.4 to 2.0 g/kg a day), nudged higher during a deficit because protein helps you keep muscle while losing fat. If your BMI is above 25, protein is worked out from your weight at a BMI of 25 rather than your full weight. Someone at 110 kg doesn't need 220 g of protein; the extra weight is mostly fat, which needs no protein upkeep.

Fat stays at 25 to 30% so hormones and fat-soluble vitamins aren't short-changed, and carbs fuel training. You don't need to hit the grams exactly. Get protein and total calories close; the carb-fat balance can float with what you like eating.

How to use your number

Pick the target, eat to it for two to three weeks, and weigh yourself on most mornings at the same time. Look at the weekly average, not single days. Water, salt and a heavy dinner can swing the scale by a kilo overnight.

• Losing faster than about 1% of body weight a week: add 100 to 200 kcal. Fast loss tends to cost muscle and makes training miserable.
• Not moving after three weeks: drop 100 to 200 kcal, or add a few thousand steps a day.
• Gaining more than about 0.5 kg a week on a bulk: most of it is fat. Pull back to the lean-gain setting.

If you have a lot to lose, start with the slower deficit. The calorie deficit and maintenance calories guide goes into how big a deficit makes sense and why "starvation mode" is mostly a myth.

Safe minimums

The calculator won't set a target below 1,200 kcal for women or 1,500 kcal for men. Below these, it gets hard to get enough protein, iron, calcium and other nutrients from food, and diets this low should be supervised by a doctor or dietitian. If your maintenance is already close to the floor (common for shorter, older or less active women), the better lever is moving more, not eating less.

Indian context

Indian meals are often heavy on carbs and cooking oil and light on protein. A typical veg thali with rice, two rotis, dal, sabzi and a sweet can easily cross 800 kcal, and the oil in a home tadka is often the biggest hidden source. Two simple moves help most people hit a deficit without feeling starved: measure the oil, and add a protein item to every meal (curd, paneer, eggs, dal, soya, chicken).

To turn the target into actual meals, build a day in the Indian food calorie counter, or start from a template like the 1,500-calorie Indian diet plan. If you're trying to gain, the weight gain diet for skinny people covers how to eat more without living on sweets.

Limitations

Every formula here predicts an average. Your real maintenance could be 200 to 300 kcal higher or lower because of genetics, muscle mass, daily steps, sleep and how accurately you log food. Thyroid conditions, PCOS, some medicines and pregnancy change energy needs; follow your doctor's advice in those cases. The tool is also built for adults; teenagers who are still growing need more than these numbers suggest.

This calculator is for general information and isn't medical advice.