How many calories should you eat to lose weight?

What is a calorie deficit?

A calorie deficit is simply taking in fewer calories than your body burns. Calories are the energy your body runs on — when you eat more than you use, the surplus is stored (largely as fat), and when you eat less, your body taps those reserves for fuel. That's what drives fat loss. You can create a deficit two ways: eat fewer calories, move more, or — best — a bit of both.

How a calorie deficit is calculated

Start with the calories you burn in a day to hold your weight steady — your Total Daily Energy Expenditure (TDEE). We estimate it from your age, sex, height, weight, and activity level with the Mifflin-St Jeor equation¹ (or Katch-McArdle if you enter your body fat %), then subtract your target deficit. Because roughly 3,500 calories equals about a pound of fat³, the math is clean:

• A deficit of about 500 calories a day → roughly 1 pound of fat loss per week.
• A deficit of about 1,000 calories a day → roughly 2 pounds per week.

So if your TDEE is 2,000 calories, eating about 1,500 a day creates a 500-calorie deficit and around a pound of loss per week. The timeline in the calculator above divides the weight you want to lose by your chosen pace.

Daily deficit and weekly weight loss

Here's how common daily deficits translate into weekly loss, using the 3,500-calories-per-pound approximation. Treat it as a starting estimate: real-world loss is faster early on and tapers as your metabolism adapts.

What's a safe, effective deficit?

For most people, a daily deficit of about 300–700 calories supports steady, sustainable loss, and 500–1,000 typically yields 1–2 pounds a week. Bigger isn't better: too steep a cut can slow your metabolism, spike hunger, and cost you muscle — which makes the weight harder to keep off. As a floor, don't routinely eat below about 1,200 calories (women) or 1,500 (men)⁵ without clinical supervision, and that minimum is often higher depending on your size and activity. (This calculator caps the targets at that floor.)

Signs your deficit is too aggressive

Cutting too much for too long tends to backfire. Ease off if you notice:

• Persistent fatigue, dizziness, or feeling cold
• Constant, distracting hunger
• Disrupted sleep or low mood
• Muscle loss — strength dropping, or the scale falling fast while you feel "softer"

A slower, well-fed pace almost always wins over the course of months.

How to create a healthy calorie deficit

The deficit is the engine, but how you create it decides whether it sticks:

• Prioritize protein. It blunts appetite and protects muscle in a deficit — set your target with our protein calculator.
• Fill up on fiber. Fruits, vegetables, beans, and whole grains keep you full on fewer calories (aim for about 25–38 g a day).
• Move more. Daily walking plus resistance training burns calories and preserves the muscle that keeps your metabolism up.
• Protect sleep and manage stress. Both drive hunger hormones and cravings — aim for 7–9 hours of sleep.
• Hydrate. Water supports metabolism and curbs appetite — see our water intake calculator.
• Get medical support if you need it. For some people, diet and willpower aren't enough — a clinician-led plan, including GLP-1 medication when appropriate, can make a sustainable deficit far more achievable.

Why weight loss stalls — and what to do

As you lose weight your body needs fewer calories, so the same intake creates a smaller deficit and progress naturally slows.² Recalculate your maintenance calories every 10–20 pounds⁴ with our TDEE calculator, then nudge your intake or activity to restore a modest deficit. Plateaus are normal — not failure. Check where you stand with the BMI calculator along the way.

This calculator provides general estimates, not medical advice or a meal plan. Calorie needs vary, and very low intakes aren't appropriate for everyone — we floor the targets at a general minimum, but you should not undertake aggressive calorie restriction without clinical guidance, especially while pregnant or breastfeeding, under 18, or on medication. It does not determine eligibility for any treatment. Talk with a JumpstartMD clinician for a plan tailored to you.

References

1. Mifflin MD, St Jeor ST, Hill LA, et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241–247. ↩
2. Hall KD, Sacks G, Chandramohan D, et al. Quantification of the effect of energy imbalance on bodyweight. Lancet. 2011;378(9793):826–837. ↩
3. Wishnofsky M. Caloric equivalents of gained or lost weight. Am J Clin Nutr. 1958;6(5):542–546. ↩
4. National Institute of Diabetes and Digestive and Kidney Diseases. Body Weight Planner. National Institutes of Health. ↩
5. U.S. Department of Agriculture & U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020–2025. ↩