Calorie Deficit Calculator
Calculate the daily calorie deficit you need to reach your weight-loss goal at a safe, sustainable pace.
In years
What Is a Calorie Deficit?
A calorie deficitis the state of eating fewer calories than your body burns. When you do, your body covers the gap by drawing on stored energy, mostly body fat, and you lose weight. Every successful diet, no matter what it's called, works by creating a deficit. Get this one variable right and the details matter far less than people think.
To build a deficit, you first need to know your maintenance calories, the amount that keeps your weight stable. This calculator estimates that figure from your age, sex, weight, height and activity level. It runs on the same engine as our TDEE calculator, then subtracts a set amount to create your deficit target. The cards above show four pacing options so you can pick one that fits your life.
How Big Should Your Deficit Be?
Bigger is not better. The right deficit is the largest one you can sustain without wrecking your energy, your training or your sanity. For most people a moderate 500-calorie deficit is ideal: it yields about 0.45 kg (1 lb) of loss per week. That is fast enough to stay motivated, gentle enough to protect muscle and adherence. A mild 250-calorie cut is even more forgiving and great for the last few stubborn kilos.
Aggressive and maximum deficits (750 to 1,000 calories) lose weight faster. The trade-offs are real: more hunger, lower energy, and a higher risk of losing muscle alongside fat. As a rule of thumb, keep weekly loss to around 0.5 to 1% of your body weight. The calculator caps every target at a safe minimum so you're never nudged into genuinely unhealthy territory.
The Math: Why 1 lb Equals About 3,500 Calories
A pound of body fat holds roughly 3,500 calories of stored energy; a kilogram holds about 7,700. That's the bridge between a daily deficit and a weekly result. Trim 500 calories a day and over seven days you've created a 3,500-calorie shortfall, about one pound of fat. Each card above does this math for you, converting the deficit into an expected weekly loss in both kilograms and pounds.
A validated example: take a moderately active person with a maintenance level of 2,759 calories. The moderate (−500) option lands on a 2,259-calorie daily target, losing roughly 0.45 kg (1.0 lb) per week. Bear in mind this is a planning estimate. Real-world loss often slows as you get lighter, which is exactly why you should recalculate periodically.
Why Crash Diets Backfire, and What to Do Instead
It's tempting to slash calories to the bone for fast results, but extreme deficits tend to sabotage themselves. They make protein and nutrient needs hard to hit, and they speed up muscle loss. They tank your energy and willpower, and they feed the binge-restrict cycle that derails so many diets. This is why the calculator will not recommend a target below the safe floor, and flags any option that would cross it.
A short, important disclaimer: this tool provides general information, not medical advice. If you have a health condition, are pregnant, or are considering an aggressive deficit, speak with a doctor or registered dietitian first. Once you've chosen a sensible target, return to maintenance periodically to recalibrate. Then run your number through the macro calculatorto make sure you're getting enough protein while you cut. Tracking your weight trend in the Velpa app makes it easy to see whether your deficit is actually working.
Frequently asked questions
- What is a calorie deficit?
- A calorie deficit means eating fewer calories than your body burns in a day. When that happens, your body makes up the shortfall by tapping into stored energy, primarily body fat, and you lose weight. It's the single mechanism behind all fat loss, regardless of which diet you follow. This calculator finds your maintenance calories first, then subtracts a chosen amount to create the deficit.
- How big should my calorie deficit be?
- For most people, a moderate deficit of 500 calories per day is the sweet spot. It produces roughly 0.45 kg (1 lb) of loss per week while still leaving enough food to feel satisfied and preserve muscle. A mild 250-calorie deficit is gentler and easier to sustain. Aggressive 750 to 1,000 calorie deficits are faster, but harder to maintain and riskier for muscle loss. A good guideline is to aim for no more than about 0.5 to 1% of your body weight per week.
- How does the 1 lb = 3,500 calories rule work?
- A pound of body fat stores roughly 3,500 calories of energy (a kilogram stores about 7,700). So a daily deficit of 500 calories adds up to 3,500 over a week, about one pound of fat. This is why the calculator translates each deficit into a weekly rate of loss. In reality the body is more complex than simple arithmetic, and the rate often slows over time. Even so, the 3,500-calorie rule remains a useful planning estimate.
- Why shouldn't I just eat as little as possible?
- Very low-calorie diets tend to backfire. They make it hard to get enough protein and micronutrients. They speed up muscle loss alongside fat. They leave you tired and hungry, and they're hard to stick to, which feeds the binge-restrict cycle. That's why this calculator never recommends a target below the safe minimum (1,500 calories for men, 1,200 for women). Slower, steady loss almost always beats a crash diet in the long run. Always consult a healthcare professional before attempting an aggressive deficit.
- Why has my weight loss stalled even though I'm in a deficit?
- Stalls are normal and usually have simple explanations. As you lose weight your maintenance calories drop, so your old deficit shrinks, so recalculate every few kilos. Day-to-day water retention from sodium, stress, hormones or a hard workout can also mask fat loss for a week or two. The fix is to track the trend over two to three weeks rather than reacting to daily numbers. It also helps to tighten up portion tracking, since calorie intake is easy to underestimate. If a true plateau lasts 3+ weeks, lower your target by another 100 to 200 calories.