What is a good calorie deficit to lose weight?

For most adults, 10 to 25% below maintenance calories, which is usually 200 to 700 kcal a day. ICMR-NIN describes a 500 to 750 kcal deficit as typical for weight loss and advises against going beyond 40% if you want to protect muscle.

How do I find my maintenance calories?

Estimate your BMR with the Mifflin-St Jeor equation, multiply it by an activity factor between 1.2 and 1.9, then check the estimate against reality: eat that amount for two to three weeks and see if your average weight holds steady.

Is 1 kg of fat really 7,700 calories?

That figure comes from the old 3,500 kcal per pound rule, and it's a rough estimate of the energy in lost tissue. It overpredicts long-term weight loss because your body burns less as you get lighter. Research by Kevin Hall and colleagues showed weight responds to a diet change slowly, with a half-time of about a year.

Why have I stopped losing weight on a calorie deficit?

Usually because your maintenance has dropped as you got lighter, portions or oil have crept up, or water retention is hiding fat loss. Recalculate maintenance at your new weight, measure food carefully for a week, and judge by a two-week average.

Does starvation mode stop weight loss?

No. Your body does adapt by burning somewhat less, often in the range of about 100 kcal a day in studies, but it doesn't stop fat loss while you remain in a real deficit. Plateaus are mostly explained by a lower body weight and less accurate tracking.

Calorie Deficit Explained: Find Your Maintenance Calories

To calculate a calorie deficit, first estimate your maintenance calories (the amount that keeps your weight steady) by working out your BMR with the Mifflin-St Jeor equation and multiplying by an activity factor. Then eat 10 to 25% less than that number. Finally, check it against reality by tracking a two-week average of your morning weight and adjusting by 100 to 200 kcal if needed.

What are maintenance calories?

Maintenance calories, also called TDEE (total daily energy expenditure), are what you burn in a day. They have two main parts:

BMR (basal metabolic rate): the energy your body uses at rest to keep you alive. For most people this is the biggest share.
Activity: everything else, from walking to the bus stop to your gym session.

If you eat more than maintenance, you gain weight over time. Eat less and you lose. That part is simple. The tricky part is getting a good estimate of the number.

How do you estimate your BMR?

The most widely used formula is the Mifflin-St Jeor equation, published in the American Journal of Clinical Nutrition in 1990:

Men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years) + 5
Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years) − 161

A 2005 systematic review by Frankenfield and colleagues found Mifflin-St Jeor was the most reliable of the common equations, predicting resting metabolic rate within 10% of measured values in more people than the others. The same review noted that older adults and ethnic minorities were underrepresented in the studies, so treat the result as a starting estimate, not a lab measurement.

Then multiply by an activity factor

These multipliers are a widely used convention, and the ones the calorie calculator uses:

Activity level	Multiplier	Looks like
Sedentary	1.2	Desk job, little or no exercise
Lightly active	1.375	Light exercise or walks 1 to 3 days a week
Moderately active	1.55	Gym or sport 3 to 5 days a week
Very active	1.725	Hard training 6 to 7 days a week
Athlete	1.9	Training twice a day, or physical job plus training

Most people with a desk job who go to the gym three or four times a week sit closer to 1.375 or 1.55 than they think. If you're unsure, pick the lower one.

Three worked examples

All three are hypothetical. BMI is included because many Indians cross into overweight at a lower number than the global cut-off. Indian guidelines use 23 for overweight and 25 for obesity, and you can check yours with the BMI calculator.

Example A: 28-year-old woman, 160 cm, 68 kg, desk job, walks 3 evenings a week

BMR = 680 + 1,000 − 140 − 161 = 1,379 kcal
Maintenance = 1,379 × 1.375 = about 1,896 kcal
15% deficit = about 1,610 kcal a day
BMI = 26.6 (obese by the Indian cut-off, overweight by the WHO's)

Example B: 35-year-old man, 172 cm, 85 kg, gym 4 days a week

BMR = 850 + 1,075 − 175 + 5 = 1,755 kcal
Maintenance = 1,755 × 1.55 = about 2,720 kcal
20% deficit = about 2,180 kcal a day
BMI = 28.7

He might be tempted to try a 1,500 kcal diet. That would be a 45% deficit. Too much.

Example C: 50-year-old woman, 155 cm, 72 kg, mostly sedentary

BMR = 720 + 968.75 − 250 − 161 = about 1,278 kcal
Maintenance = 1,278 × 1.2 = about 1,533 kcal
10% deficit = about 1,380 kcal a day
BMI = 30.0

A 20% deficit would put her at about 1,227 kcal, right at the usual unsupervised floor of 1,200 for women. For her, the better lever is moving more. Adding daily walks and moving up to the 1.375 multiplier raises maintenance to about 1,757 kcal, which gives her room for a proper deficit while still eating around 1,400 to 1,500. Structured easy cardio like zone 2 training helps here.

How big should your deficit be?

Deficit	Example A (1,896)	Example B (2,720)	When it fits
10%	about 1,707	about 2,448	Close to your goal, older, or very lean
15%	about 1,612	about 2,312	A good default for most people
20%	about 1,517	about 2,176	Plenty to lose, training regularly
25%	about 1,422	about 2,040	Short phases only, with high protein

The official guidance points to the same range:

ICMR-NIN's Dietary Guidelines for Indians 2024 describe a 500 to 750 kcal deficit as typical, advise against going beyond 40% to protect muscle, and consider losing about half a kilo a week safe.
The NHS suggests aiming for 0.5 to 1 kg a week.
For people who lift, a 2014 review on contest preparation (Helms et al.) recommends losing about 0.5 to 1% of body weight a week to hold on to muscle.

Don't go below about 1,200 kcal a day for women or 1,500 for men without medical supervision. If you're pregnant, breastfeeding, under 18, have diabetes on medication, kidney disease or a history of an eating disorder, talk to a doctor before you start.

Protein matters more in a deficit. ICMR-NIN notes that getting at least 15% of your calories from protein during a 500 to 750 kcal deficit helps preserve muscle.

Is "3,500 calories = 0.45 kg of fat" true?

Only as a rough short-term guide. The rule says a pound (0.45 kg) of fat holds about 3,500 kcal, which works out to roughly 7,700 kcal per kg. So a 500 kcal daily deficit "should" mean about 0.45 kg a week, every week, forever.

It doesn't work that way. In a 2011 Lancet paper, Kevin Hall and colleagues showed that body weight responds to a lasting change in intake slowly, with a half-time of about a year, because your energy needs fall as you get lighter. They called the 3,500 kcal rule inappropriate for predicting long-term change and proposed a different rule of thumb: every 100 kJ (about 24 kcal) a day of sustained change in intake leads to about 1 kg of eventual weight change for an average adult.

Here's what that means for a 500 kcal daily cut:

Method	Predicted loss
3,500 kcal rule, after 1 year	500 × 365 ÷ 7,700 = about 24 kg
Hall rule of thumb, eventual total	500 ÷ 24 = about 21 kg, reached over several years
Hall model, after 1 year	roughly half of that, about 10 kg

Both are averages for adults, and people with more body fat tend to lose more for the same change. But the lesson holds: weight loss slows over time even when you change nothing, and that's normal, not failure.

Why does weight loss plateau?

You weigh less, so you burn less. Example A at 63 kg has a maintenance of about 1,827 kcal, about 70 kcal lower than at 68 kg. Recalculate every 4 to 5 kg.
Your body adapts a little. This is real but modest. In a 2024 study of people who lost about 18 kg in 10 weeks, resting energy use was about 121 kcal a day lower than predicted, and the authors expected this to shrink once weight stabilised. "Starvation mode" that stops fat loss altogether isn't supported by this kind of evidence.
Portions creep. The extra spoon of oil, the second biscuit with chai, the weekend that turns into Friday to Sunday. Measure oil and log everything for one week.
Water hides fat loss. Salt, a heavy dinner, a hard leg day or your period can push the scale up for a few days.

How to track with a two-week average

Single weigh-ins lie. A two-week average doesn't, or at least lies much less.

Weigh yourself 4 or more mornings a week, after the toilet, before food or water.
Average weeks 1 and 2 together. Then average weeks 3 and 4.
Compare the two averages.

A hypothetical example:

	Weigh-ins (kg)	Average
Weeks 1 to 2	72.4, 72.0, 72.6, 71.9, 71.8, 72.1, 71.5, 71.7	72.0
Weeks 3 to 4	71.6, 71.2, 71.9, 71.3, 71.0, 71.4, 70.9, 71.2	71.3

That's about 0.7 kg over two weeks, or about 0.35 kg a week. Notice that the scale went up from 71.2 to 71.9 at one point. Without the average, that day might have felt like failure.

Adjust like this:

Losing within your target: change nothing.
No change in the average after 3 to 4 weeks: cut 100 to 200 kcal, or add activity.
Losing much faster than 1% of body weight a week: add 100 to 200 kcal back.

To turn your target into actual meals, log a typical day in the Indian food calorie counter, or use the Indian food calorie chart for quick numbers. If your target lands around 1,500, the 1,500 calorie Indian diet plan is a ready-made week.

Quick checklist

Estimate BMR with Mifflin-St Jeor, multiply by an honest activity factor
Eat 10 to 25% below that; 15% is a good default
Stay above about 1,200 kcal (women) or 1,500 kcal (men) without supervision
Keep protein high and keep lifting while you diet
Expect loss to slow over time; recalculate every 4 to 5 kg
Judge progress by two-week averages, then adjust by 100 to 200 kcal

This is general information, not medical advice.