Calorie Deficit Calculator - Daily Intake for Weight Loss

Rule of thumb	3,500 kcal ≈ 1 lb fat
0.5 kg/week	≈ 550 kcal/day deficit
Sustainable rate	0.5–1% of body weight/week
Output	Daily intake target

What is Calorie Deficit Calculator?

A calorie deficit is the gap between the energy you burn and the energy you eat. It is the only mechanism that produces fat loss. The calculator takes your maintenance calories and subtracts a deficit sized to your chosen weekly loss rate — so the target is derived from a pace you can actually sustain rather than an arbitrary number. A deficit of 0.5–1% of body weight per week is generally considered sustainable: faster loss tends to cost muscle and is harder to maintain, while slower loss is easy to abandon because progress feels invisible. The output is a daily intake target. Because real energy expenditure varies, treat it as a starting point and adjust after two to three weeks of weight data.

Common Uses for Calorie Deficit Calculator

Turn a weight-loss goal into a daily calorie target
Compare how different weekly rates change your intake
Set a realistic deficit rather than an extreme one
Recheck your deficit after losing weight

Frequently Asked Questions

What is a safe calorie deficit?

A deficit of 300–600 kcal a day, producing 0.5–1% of body weight loss per week, is generally sustainable. Very large deficits risk muscle loss, fatigue and rebound. Some people should not diet without medical supervision.

Why does my weight loss stall on a deficit?

As you lose weight, maintenance falls and the same intake becomes a smaller deficit. Water retention can also mask fat loss for one to two weeks. Recalculate and, if needed, trim intake or add activity.

Can I create the deficit with exercise instead of food?

Yes, but food is the easier lever — an hour of running burns roughly 500–700 kcal, about the same as skipping one large meal. Most sustainable plans use both.

Should I eat at my deficit every day?

Daily consistency is simpler. Weekly averaging also works: a larger deficit on some days and maintenance on others can improve adherence while producing the same weekly total.