How Big Should Your Calorie Deficit Be?
Most people lose weight safely with a 300–500 calorie deficit. Use the calculator below to find your exact number based on your body and goals.
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Most people lose weight safely with a 300–500 calorie deficit. Use the calculator below to find your exact number based on your body and goals.
Find out exactly how many calories you should eat to lose weight safely
Know your number? Now track it automatically.
465cal uses AI to log your meals from photos — no more manual entry.
A calorie deficit means eating fewer calories than your body burns. When you maintain a deficit consistently, your body uses stored fat for energy — and you lose weight.
The size of your deficit determines how fast you lose weight:
For most people, a 500-calorie deficit is the sweet spot. It's aggressive enough to see results within weeks, but sustainable enough that you won't feel starved or burn out.
Here's the truth: most people who "can't lose weight" aren't actually in a deficit. They think they are — but hidden calories from cooking oils, sauces, and portion sizes add up fast.
Studies show people underestimate their intake by 40-50%. That's the difference between losing weight and gaining it.
The solution? Track consistently. But we know manual logging is tedious (5-10 minutes per meal). That's exactly why we built 465cal — snap a photo, and AI does the rest in 3 seconds.
Yes, for most adults a 500-calorie deficit is considered safe and sustainable. It leads to roughly 1 pound of weight loss per week. However, you should never go below 1,200 calories (women) or 1,500 calories (men) without medical supervision.
The most reliable sign is consistent weight loss over 2-4 weeks. If the scale isn't moving, you're likely eating more than you think. Accurate tracking is essential — which is why photo-based AI tracking is so valuable.
The most common reasons: 1) You're not actually in a deficit (tracking errors), 2) Water retention is masking fat loss, 3) You've been dieting too long and need a diet break. If you're not tracking every bite accurately, start there.
Most experts recommend deficit phases of 8-16 weeks, followed by 1-2 weeks at maintenance calories. This prevents metabolic adaptation and keeps your body responsive to the deficit.
Technically yes — weight loss is about total calories. But protein, fiber, and nutrients matter for muscle retention, energy, and health. Aim for 80% whole foods, 20% flexibility.
The hardest part of weight loss isn't knowing your number — it's logging every meal accurately. That's where most people fail.
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Medical Review by 465Cal Nutrition Team • Fact-checked for accuracy