Calorie calculator: how much to eat to lose, maintain or gain

Your starting calories are estimated maintenance, adjusted for your goal. The calculator above uses the same Mifflin–St Jeor equation, activity factors, pace adjustments and macro rules as HeyCoach. It shows the result before you decide whether to use it.

The number is a starting estimate, not a measurement of your metabolism. Two real weeks of food and weigh-ins tell you whether it is right.

Where the number comes from

First, the tool estimates resting energy:

10 × kg + 6.25 × cm − 5 × age + sex constant

The constants are +5 for men and −161 for women. The unspecified option uses −78, which is simply the midpoint of the two rather than a separately validated equation. Then the resting estimate is multiplied by activity. Mifflin et al., the original equation

Those three are HeyCoach's own categories. Choose the one that describes your whole week, not your most ambitious workout. Our TDEE guide explains why the activity assumption is where calculators usually part ways.

What the goal selector changes

Maintenance keeps the estimated energy total. Weight loss subtracts 275, 550 or 825 kcal/day for requested paces of 0.25, 0.5 or 0.75 kg/week. Gain adds the corresponding amount.

The pace labels come from a flat energy conversion, so your scale will not follow them to the decimal, and a faster gain setting buys more weight, not more muscle. Start with a gentler pace and let your own trend argue for a faster one.

The output includes protein at 1.8 g/kg for loss, 1.6 for maintenance and 2.0 for gain; fat at about 27% of calories; carbohydrate as the remainder. If an unusual weight-and-calorie combination makes those macros impractical, the tool says so. Sharing the formula with the coach means the website and the chat always agree; it still takes a sensible input to get a sensible plan.

A worked starting plan

For a 35-year-old woman at 170 cm and 80 kg, moderate activity produces:

• Resting estimate: 1,526.5 kcal/day.
• Maintenance estimate: 2,213 kcal/day.
• Standard loss target: 1,663 kcal/day.
• Protein: 144 g, fat: 50 g, carbohydrate: 159 g.

You do not need to hit every gram. The point is a repeatable starting line that fits a real day of meals. Our calorie-target guide explains how to test it.

What happens when the minimum applies

Targets have a safe floor: 1,200 kcal for women, 1,500 for men and 1,350 for the unspecified option. If your chosen pace would take you below it, the calculator raises the target to the floor and stops quoting a date, because the pace you asked for is no longer the pace you would get.

The floor is a floor, not a recommendation; many adults need a good deal more. If you are pregnant, breastfeeding, in eating-disorder care, training intensively or managing a medical condition, your number comes from a professional who knows you. The calculator is built for adults 20 and older.

The goal-weight field also refuses anything below adult BMI 18.5. Clearing that bar makes a goal possible, not automatically right for you.

How to read the date

This calculator shows the coach's fixed-pace estimate: it assumes you keep changing weight at the rate you picked. For loss, that gets less realistic the longer the plan runs, because a lighter body burns less.

Use the calorie deficit calculator to set the flat estimate beside a simplified curve that slows. For a personalized dynamic scenario, explore the NIDDK Body Weight Planner.

A date is there to organize the plan. If the scale moves differently, the answer is a fresh look at the estimate, not a lower and lower intake.

FAQ

Why does another calculator give me different calories?

It may use a different resting equation, activity multiplier, pace adjustment or minimum. Compare assumptions before deciding one output is more accurate.

Does the WhatsApp button save my plan?

No. It opens a message containing your inputs and result. You review and send it, then the coach confirms your details during setup.

Should I add exercise calories again?

Usually not. Your activity factor already includes some movement, so adding the same workout twice overstates maintenance. Pick one approach, stay consistent and let your trend judge it.

The easy way to do this

This is the exact formula HeyCoach runs at onboarding, so the plan on this page is the plan the coach will hold you to. Message it and your targets are set in about 30 seconds, with no app to download. From then on a photo or one line logs a meal, a reply corrects a portion even days later, and the coach remembers your targets so you never type them in again. The number stays beside the meals that test it.