Fill in every field above to see your target.
Your target has been raised to the floor this calculator will not go below: 1,200 calories a day for women, 1,500 for men, following the NIH weight-management guidelines. Eating under that belongs with a clinician, not a calculator.
How this calculator works
It runs the same three steps the MyPlate app runs, with the same constants. Nothing here is tuned to sell you anything. The numbers are the published ones, and every source is listed on our health sources page.
Step 1: Your BMR
Basal metabolic rate is what your body burns doing nothing at all: breathing, circulating blood, keeping your brain and organs going. It comes from the Mifflin-St Jeor equation, published in 1990 and still the best-performing of the common formulas when they were compared against measured metabolic rate in 2005.
BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + s
where s = +5 for men and −161 for women
Step 2: Your maintenance calories
BMR only covers rest. Multiply it by a physical activity level (PAL) for everything else you do, and you get total daily energy expenditure: the calories that hold your weight where it is.
| Activity | Workouts a week | Multiplier |
|---|---|---|
| Low | 0–1 | 1.375 |
| Moderate | 2–3 | 1.55 |
| High | 4–6 | 1.725 |
| Very high | 6+ | 1.9 |
Step 3: Your goal
A weight-loss goal takes 15% off that number and a weight-gain goal adds 10%. Both keep the change gradual rather than producing a crash deficit that you abandon in a fortnight. Whatever the arithmetic produces, the target never drops below 1,200 calories a day for women or 1,500 for men.
That floor does more work than it looks like it does. A deficit written as a percentage scales down with the person, so a small, older, sedentary profile can compute a target nobody should eat without supervision. Both this page and the app clamp it.
Your protein, carbs and fat
Your macronutrient targets are shares of the calorie number, kept inside the Acceptable Macronutrient Distribution Ranges from the Dietary Reference Intakes (protein 10–35% of energy, carbohydrate 45–65%, fat 20–35%). Grams come from the Atwater factors: 4 calories per gram of protein and of carbohydrate, 9 per gram of fat.
| Goal | Protein | Carbs | Fat |
|---|---|---|---|
| Lose weight | 28% | 45% | 27% |
| Maintain | 25% | 47% | 28% |
| Gain weight | 25% | 49% | 26% |
Protein sits at the higher end for weight loss on purpose: it is the macro that most protects lean mass while you are in a deficit, and it keeps you full longer per calorie.
Frequently asked questions
How many calories should I eat a day to lose weight?
Take your maintenance calories and subtract 15%. That pace sits inside the gradual range health authorities recommend, and it is the adjustment this calculator and the MyPlate app both apply for a weight-loss goal. Counting calories to lose weight only works if you can hold the deficit for months, which is why the number is not more aggressive. It is also never allowed below 1,200 calories a day for women or 1,500 for men.
What is the difference between BMR and TDEE?
BMR is what your body burns at complete rest, keeping your heart, brain and organs running. TDEE, or total daily energy expenditure, is your BMR multiplied by an activity factor for everything you do on top of that. It is shown above as your maintenance calories. You eat against TDEE, not BMR.
Which calorie formula is the most accurate?
Mifflin-St Jeor, which is what this calculator uses. When Frankenfield and colleagues compared the published equations against measured metabolic rate in 2005, Mifflin-St Jeor came within 10% of the measured value more often than Harris-Benedict or the others. It is still an estimate built for a population, not a measurement of you.
What is the best way to track macros for weight loss?
Set the split first, then log against it. This calculator gives you protein, carb and fat targets in grams; a macro tracking app has to tell you what you actually ate. Weigh or photograph the food rather than reconstructing it from memory, log it the same day, and judge the week rather than any single day. Most people who give up on macro tracking for weight loss give up over the logging, not the arithmetic.
Why is my calorie target lower than the calculator's?
Any equation is a starting point. Your real expenditure depends on body composition, medication, sleep, how much you move outside the gym, and how honest you were about the activity level you picked. Log what you actually eat for two or three weeks and watch which way your weight moves, then adjust the target to match what you measured.
The hard part is the logging
The number above takes ten seconds to produce. Hitting it every day is the part people give up on, because logging a meal by searching a database and guessing at portion sizes gets tedious fast.
That is what the app is for. MyPlate is a calorie counter and food tracker that works from a photo: point the camera at your plate and the calories and macros land in your food log, against the same targets this page calculates. If you are starting from scratch, there is also a guide to counting calories without losing your mind.
This is not medical advice
This calculator provides general nutrition information for self-tracking. It is not medical advice, a diagnosis, or a treatment plan, and the targets it produces are estimates from published formulas, not a prescription written for you.
Talk to a doctor or a registered dietitian before acting on these numbers if you are under 18, pregnant or breastfeeding, have ever had an eating disorder or a difficult relationship with food, are managing a medical condition, or have been put on a specific diet by a clinician.