The toolbox · Health
How many calories do you need?
Enter a few details and see the calories your body burns in a day — plus exactly how much to eat to lose, maintain or gain weight. Updates as you type.
- More than one number. Your BMR, daily maintenance calories, and targets for each goal.
- Metric or imperial. Switch between kg/cm and lb/ft-in with a tap.
- Instant & private. Worked out in your browser — nothing you enter is sent to us.
Maintain your weight
— kcal / day
Basal metabolic rate (BMR): — kcal
BMI — · —
Mild weight loss
— kcal
Weight loss
— kcal
Mild weight gain
— kcal
Weight gain
— kcal
The current dietetics standard — the best general-purpose estimate.
The older 1919/1984 equation, kept so you can compare.
Based on lean body mass — the most accurate, if you know your body fat.
Worked out in your browser — nothing you enter is sent to us.
Your daily macros
How those calories split into protein, carbohydrate and fat.
— kcal / day
Protein
— g
—% of calories
Carbohydrate
— g
—% of calories
Fat
— g
—% of calories
Protein and carbohydrate carry 4 kcal per gram, fat 9. These splits are common starting points, not a prescription — a dietitian can tailor them to you.
Your BMI
—
- International (WHO)
- —
- WHO Asia-Pacific
- —
Health risk rises at a lower BMI in South Asian populations, so the WHO's Asia-Pacific thresholds (overweight from 23, not 25) are the ones most relevant to readers in India. BMI ignores muscle and body composition — it is a screening figure, not a diagnosis.
The science
How your daily calories are worked out
Two steps: estimate the energy your body burns at rest, then scale it up for how active you are.
Your BMR
Basal Metabolic Rate is the energy you'd burn doing nothing all day. We default to Mifflin-St Jeor — the equation dietetics practice now treats as the standard — with Harris–Benedict and lean-mass-based Katch-McArdle a tap away.
Your activity
Multiply BMR by an activity factor — from 1.2 (sedentary) up to 1.9 (very hard exercise or a physical job) — to get your maintenance calories, or TDEE.
Your goal
To lose weight, eat below maintenance; to gain, eat above. Roughly 500 kcal a day maps to about half a kilo (one pound) a week.
A worked example
Take a 30-year-old man, 180 cm and 75 kg, who is moderately active. By Mifflin-St Jeor his BMR is about 1,730 kcal, and at an activity factor of 1.55 he burns roughly 2,682 kcal a day — his maintenance calories. To lose about half a kilo a week he'd eat near 2,182 kcal; to gain, about 3,182 kcal. His BMI is 23.1, and on a balanced 30/40/30 split those maintenance calories are roughly 201 g protein, 268 g carbohydrate and 89 g fat a day. Change the calculator above to see your own numbers.
The Calorie Calculator is one of DriveBird's free tools. If you like planning by the numbers, our EMI calculator does the same for a loan, and a fresh daily quote is never a bad way to start a healthy habit.
This calculator gives a general estimate and isn't medical or dietary advice. For a plan tailored to you, talk to a doctor or a registered dietitian.
Calorie calculator — frequently asked questions
How many calories should I eat a day?
It depends on your sex, age, size and activity. Enter them above to get your maintenance calories — the amount that keeps your weight steady — then eat below it to lose weight or above it to gain. As a rough guide, many adults sit somewhere between 1,600 and 3,000 kcal a day.
What is BMR and TDEE?
BMR (Basal Metabolic Rate) is the energy your body uses at complete rest. TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor — it's the number of calories you actually burn in a typical day, which we label "maintain your weight".
How accurate is this calorie calculator?
It defaults to the Mifflin-St Jeor equation, which studies find the most reliable general-purpose estimate — but everyone's metabolism differs. If you know your body-fat percentage, Katch-McArdle will do better still. Treat the result as a starting point, track your weight over a couple of weeks, and adjust up or down as needed.
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