Find a target daily calorie amount for a chosen deficit.
Your maintenance calories (TDEE) minus your chosen daily deficit gives a target intake.
Target: Maintenance − deficit
Weekly loss: ≈ Deficit × 7 ÷ 7700
The calorie deficit calculator turns a weight-loss plan into two numbers: how many calories to eat each day, and roughly how much weight that deficit could remove per week. You enter your maintenance calories, which is your TDEE, and the daily deficit you want, and it subtracts one from the other and converts the weekly deficit into kilograms using the 7,700 kcal per kg rule.
Almost every weight-loss approach, whether it is a diet plan, intermittent fasting or cutting sugar, works by creating a calorie deficit. Putting a number on it helps people choose a pace they can sustain. A moderate daily deficit of a few hundred calories usually fits around Indian meals without constant hunger, while very large deficits are harder to keep and are best discussed with a doctor or dietitian.
1. Estimate your maintenance calories from BMR × activity multiplier, or from a period when your weight was stable.
2. Choose a daily deficit, often 300 to 500 kcal for a steady pace.
3. Target intake = Maintenance − Deficit.
4. Weekly deficit = Daily deficit × 7.
5. Estimated weekly loss in kg = Weekly deficit ÷ 7,700.
6. Check your weight trend every two weeks and adjust the target if it differs from the estimate.
When you eat less energy than you use, the body makes up the gap from its stores, mostly fat but also some glycogen and protein. This is energy balance: change in stored energy equals intake minus expenditure. The calculator uses your maintenance figure as expenditure and your target as intake, so the deficit is the gap. How the deficit is created, by eating less, moving more or both, matters for hunger and muscle retention, but not for the arithmetic.
Body fat tissue is not pure fat. It is about 85% to 90% lipid, with the rest water and cell structure. Fat yields about 9 kcal per gram, so a kilogram of fat tissue stores roughly 7,700 kcal. The older rule of 3,500 kcal per pound is the same idea in imperial units. The calculator divides the weekly deficit by 7,700 to estimate kilograms of fat lost, which is a useful approximation, not a guarantee.
In the first week or two, weight often drops faster than the formula predicts, because lower carbohydrate stores release water. Later, loss slows: a smaller body needs fewer calories, so the same intake gives a smaller deficit, and the body adapts slightly to spend less. Day-to-day weight also swings with salt, water and digestion. That is why the estimate is best compared with a two-to-four-week trend, and the target recalculated as weight changes.
Neha's maintenance is about 2,450 kcal a day according to her TDEE, and she wants a gentle 400 kcal daily deficit she can keep up during the festival season.
Answer: Target daily calories 2,050 kcal; Estimated weight loss per week 0.36 kg
Choosing a very large deficit that leads to fatigue, muscle loss and rebound eating.
Expecting exact weekly losses and giving up when the scale fluctuates.
Using an inflated maintenance estimate, which means the real deficit is smaller than planned.
Forgetting to lower the target as body weight falls.
Setting an intake below BMR for long periods without advice from a doctor or dietitian.
Setting a daily calorie target for weight loss.
Choosing a realistic pace for losing weight before an event.
Checking whether a diet plan's calories match the intended weekly loss.
Explaining energy balance in nutrition and biology lessons.
Is 500 kcal/day a safe deficit?
A 500 kcal/day deficit (about 0.5 kg lost per week) is a commonly used, moderate approach. But everyone is different, and very large deficits are usually not recommended without a doctor's guidance.