How big should a calorie deficit be?

500 calories a day below what you burn gives about a pound a week. 750 to 1,000 is aggressive and harder to hold. Below 1,200 calories a day for women or 1,500 for men should be doctor-supervised.

Why is my goal date so far away?

Because the math is honest: 3,500 calories per pound, at the pace you chose. A larger deficit shortens it but is harder to keep up, and this calculator won't go below the safe floor.

Will I lose weight at exactly this rate?

No. The first two weeks usually show more loss from water, then it slows as you get lighter and burn less. Re-run the calculator every 10 pounds.

What if I can't stay under the target?

Hunger is the usual reason, not discipline. GLP-1 medication works on appetite, which is why people find a deficit easier to hold on it. A doctor reviews whether it fits you.

Free tools

Calorie deficit calculator

A calorie deficit is eating less than you burn. This calculator works out what you burn, subtracts the deficit for the pace you choose, and shows the daily target and a realistic date. It also won't let the target drop below the level that needs a doctor's supervision.

Sex

Age

years

Height

Weight

Activity

Goal weight

Pace

Daily calorie target

1,448kcal

You burn

1,948 kcal

Daily deficit

500 kcal

Goal date

February 25, 2027 (20 weeks)

Based on 3,500 calories per pound. Loss is rarely a straight line: water shifts in the first two weeks, then it slows as you get lighter. Re-run this every 10 pounds.

If the target feels impossible to hold

That's usually hunger, not willpower. GLP-1 medication changes appetite so the deficit is easier to keep, from $129 a month with the price locked at every dose.

See GLP-1 weight loss

Free doctor review, usually within 24 hours. You're not charged unless they write the prescription.

Common questions

How big should a calorie deficit be?: 500 calories a day below what you burn gives about a pound a week. 750 to 1,000 is aggressive and harder to hold. Below 1,200 calories a day for women or 1,500 for men should be doctor-supervised.
Why is my goal date so far away?: Because the math is honest: 3,500 calories per pound, at the pace you chose. A larger deficit shortens it but is harder to keep up, and this calculator won't go below the safe floor.
Will I lose weight at exactly this rate?: No. The first two weeks usually show more loss from water, then it slows as you get lighter and burn less. Re-run the calculator every 10 pounds.
What if I can't stay under the target?: Hunger is the usual reason, not discipline. GLP-1 medication works on appetite, which is why people find a deficit easier to hold on it. A doctor reviews whether it fits you.

More tools

BMI calculatorYour body mass index and the healthy weight range for your height TDEE calculatorThe calories you burn in a day, including activity Protein calculatorGrams of protein a day for your weight and goal Water intake calculatorHow much to drink a day for your weight, exercise and climate

These calculators give estimates from standard formulas for healthy adults. They are not medical advice and don't account for pregnancy, medical conditions or medications. Decisions about treatment are made by the licensed providers in our network.