TDEECalculator.AI

Calorie Deficit Calculator

Find how many calories to eat to lose weight, and whether your pace is safe for your body.

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Short answer

To lose about 1 lb a week, eat roughly 500 calories a day below your TDEE. A better way to choose your pace is by body weight: losing 0.5–1% of your weight a week is the sweet spot for most people.

Deficit by weekly pace

Goal per weekDaily deficit
0.5 lb (0.25 kg)250–275 calories
1 lb (0.5 kg)500–550 calories
1.5 lb (0.75 kg)750–825 calories
2 lb (1 kg)1,000–1,100 calories

These are starting estimates. Weight loss slows over time because a smaller body burns less, so the same deficit removes less weight in month three than in month one.

Why we rate your pace by % of body weight

Losing 2 lb a week means something very different at 130 lb than at 250 lb. So after you calculate, we rate each pace against your own weight:

Rating% of body weight a week
GentleUnder 0.5%
Sweet spot0.5–1%
Aggressive1–1.5%
Too fastOver 1.5%

Slower is kinder to your muscle. In a study of elite athletes who lifted weights while dieting, the group losing 0.7% of body weight a week gained more lean mass and strength than the group losing 1.4% a week, even though both lost about the same amount overall.

Example: same pace, different bodies

A 35-year-old woman who is 5 ft 5 in, 165 lb and lightly active has a TDEE of about 1,986 calories a day.

Pace% of her weightDaily caloriesRating
0.5 lb0.3%1,736Gentle
1 lb0.6%1,486Sweet spot
1.5 lb0.9%1,236Sweet spot
2 lb1.2%1,200*Aggressive

*Her math says 986, so we cap it at 1,200, the usual safe minimum for women without medical supervision.

For someone who weighs 250 lb, the same 2 lb a week is only 0.8% of body weight, which is right in the sweet spot.

How low is too low?

We won't set a target below about 1,200 calories a day for women or 1,500 for men. Below that, it's hard to get enough protein, vitamins and minerals, and you'll lose more muscle. If your burn is already close to those numbers, moving more is the safer lever.

Make your deficit work

  • Keep protein high, about 0.7–1 g per lb of body weight, to protect muscle.
  • Lift weights 2–3 times a week if you can.
  • Weigh in 3–4 mornings a week and compare weekly averages, not single days.
  • Recalculate every 10–20 lb (5–10 kg).

Stuck? Read why you're not losing weight in a calorie deficit.

More calculators

Not medical advice. These numbers are estimates for healthy adults aged 18–80, based on published equations. They aren't reviewed by a doctor or registered dietitian. Talk to one before making big changes to how you eat, especially if you're pregnant or breastfeeding, under 18, have a history of disordered eating, have a medical condition, or take medication that affects appetite or weight. Medical disclaimer

Sources

  1. Garthe I, et al. Effect of two different weight-loss rates on body composition and strength and power-related performance in elite athletes. Int J Sport Nutr Exerc Metab, 2011.
  2. Hall KD, et al. Quantification of the effect of energy imbalance on bodyweight. Lancet, 2011.
  3. Hall KD, Chow CC. Why is the 3500 kcal per pound weight loss rule wrong? Int J Obes, 2013.