What Is a Calorie Deficit?
A calorie deficit means eating fewer calories than your body uses in a day. When you are in a deficit, your body makes up the shortfall from stored energy, mostly body fat. Over weeks, that shows up as weight loss.
Every calorie deficit starts from your maintenance calories: the amount you would need to eat to keep your weight exactly the same. This calculator works out your maintenance calories first. It then subtracts (or adds) the right amount for the weekly rate you choose.
⚖️Eat below maintenance: lose weight
A deficit of about 550 kcal a day works out to roughly 0.5 kg (1 lb) of fat loss per week.
🎯Eat at maintenance: hold your weight
Useful after a diet phase, or for building better habits without changing the scale.
💪Eat above maintenance: gain weight
A small surplus with strength training supports muscle gain while limiting fat gain.
How This Calorie Deficit Calculator Works
The calculator uses the same Mifflin-St Jeor equation as our TDEE Calculator, so the two tools always agree. The calculation has three steps:
Step 1: BMR
Men: (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5
Women: (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161
Step 2: Maintenance calories
TDEE = BMR × activity factor
The factor ranges from 1.2 (sedentary) to 1.9 (extra active).
Step 3: Daily target
Daily deficit = (kg per week × 7,700) ÷ 7
1 kg of body fat stores roughly 7,700 kcal. Your target is TDEE minus the deficit (or plus a surplus to gain).
How Big Should Your Calorie Deficit Be?
Faster is not better. A bigger deficit makes you hungrier, costs more muscle and is harder to keep up. Most people do best with a mild or moderate rate.
| Rate | Weekly loss | Daily deficit | Best for |
|---|
| Mild | 0.25 kg (0.5 lb) | ~275 kcal | Close to goal weight, or training hard |
| Moderate | 0.5 kg (1 lb) | ~550 kcal | Most people, and the most sustainable option |
| Aggressive | 0.75 kg (1.5 lb) | ~825 kcal | Larger amounts to lose, for short periods |
| Maximum | 1 kg (2.2 lb) | ~1,100 kcal | Only with plenty of weight to lose and medical guidance |
Built-in safety floor:
This calculator never plans a deficit that takes you below 1,200 kcal/day for women or 1,500 kcal/day for men, or 1.2× your BMR, whichever is higher. If your chosen rate would go below that, it caps the rate and tells you, rather than showing an unsafe number. If your maintenance calories are already below that minimum, it suggests no deficit at all and recommends talking to a doctor or dietitian.
Maintenance Calories: The Number Everything Else Builds On
Your maintenance calories (also called TDEE) are the calories you burn in a typical day. They come from three sources:
- Basal metabolic rate (60-70%): keeping you alive at rest. Read more in our guide to BMR.
- Physical activity (15-30%): everything from walking to workouts.
- Digesting food (~10%): the thermic effect of food, which is highest for protein.
Maintenance calories are not fixed. As you lose weight, your BMR drops a little. Recalculate every 4-6 weeks or after every 3-5 kg of change so your target stays accurate.
Pick your activity level honestly:
Most people overestimate their activity. With a desk job and 3 workouts a week, "Lightly Active" is usually closer than "Moderately Active". If you lose weight faster or slower than expected over 2-3 weeks, adjust your intake by 100-200 kcal.
How to Eat in a Calorie Deficit on an Indian Diet
You don't need to give up Indian food to eat in a deficit. Most of the change comes from portions, cooking oil and protein:
🥘Measure oil and ghee
One tablespoon of oil is about 120 kcal. Tadka and deep-frying add up fast. Measuring the oil is often the single biggest win.
🍚Manage rice and roti portions
Keep your staples, but fix the portion. Fill half the plate with sabzi and salad so the meal still feels full.
🥚Prioritise protein
Dal, paneer, curd, eggs, chicken and fish keep you full and protect muscle. Find your number with the Protein Calculator.
