Calorie deficit calculator.

You know your maintenance calories; now turn them into an eating target. Pick a weekly pace and get the daily number — plus the size of the deficit itself, so nothing about the plan is a mystery.

The math: a kilogram of body fat represents roughly 7,700 kcal (≈3,500 kcal per pound), so your chosen weekly pace divided across seven days gives the daily deficit, and your target is maintenance minus that deficit. Guidance, not medical advice — anyone with a medical condition or a history of disordered eating should plan intake with a professional.

Why the moderate deficit wins

A bigger deficit looks faster on paper, and for the first two weeks it usually is. Then the costs show up. Large deficits burn muscle along with fat, drag down training quality and daily energy, and — most decisively — collapse adherence: the diet that ends in week five loses to the smaller deficit that runs for six months, every time. Hunger scales with the size of the cut, and willpower doesn’t.

Two guardrails keep a plan on the sustainable side:

• Respect the floor. Health authorities commonly cite around 1,200 kcal per day for women and 1,500 for men as minimums below which meeting nutrient needs gets genuinely difficult without supervision. If your target lands down there, the fix isn’t grit — it’s a gentler pace.
• Audit before you cut deeper. If the scale stalls, the deficit on paper usually isn’t the deficit in practice — untracked bites, oils and weekend meals close the gap quietly. Work through why a calorie deficit stops working before shrinking the target again.

Want to see where your chosen pace actually lands you on the calendar? The weight-loss timeline calculator turns the same pace into a realistic goal-weight date.