This calorie deficit calculator tells you how many calories to eat each day to lose weight at the pace you choose, and how many weeks it will take to reach your goal. It starts from your maintenance calories, then subtracts a deficit of 250 to 1,000 kcal and checks that the target stays above safe limits.
A deficit is simply eating less energy than you burn. The body covers the gap from stored fat, at about 7,700 kcal per kg. Slow and steady keeps more muscle and is far easier to stick with.
Quick numbers
Energy in 1 kg of fat
about 7,700 kcalDeficit for 0.5 kg a week
about 550 kcal a daySafe pace
0.25 to 1 kg a weekFloor without supervision
1,200 kcal women, 1,500 kcal menBest partner
high protein and strength training
How the calorie deficit calculator sets your target
- Step one is BMR, from Mifflin St Jeor.
- It multiplies by your activity level to get maintenance (TDEE).
- It subtracts the deficit for your chosen pace.
- It checks the result against the minimum intake for your sex and warns you if it is too low.
- It divides the weight you want to lose by your weekly loss to give a time frame.
If you want to see each step on its own, the BMR tool and the TDEE tool show them.
Calorie calculator to lose weight: worked example
A 32 year old woman, 165 cm, 70 kg, light activity. Maintenance is about 1,939 kcal. With a 500 kcal deficit she eats about 1,439 kcal a day. To lose 6 kg at roughly 0.45 kg a week takes about 13 to 14 weeks.
| Weight | Maintenance | Deficit 300 | Deficit 500 | Room above 1,200 |
|---|---|---|---|---|
| 60 kg | 1,802 | 1,502 | 1,302 | 600 |
| 70 kg | 1,939 | 1,639 | 1,439 | 740 |
| 80 kg | 2,077 | 1,777 | 1,577 | 880 |
| 90 kg | 2,214 | 1,914 | 1,714 | 1,010 |
The last column shows how much space there is above the 1,200 kcal floor. At lower weights, a large deficit quickly runs into that limit, so the pace has to be slower.
How big should the deficit be
| Deficit a day | Loss a week | Best for |
|---|---|---|
| 250 kcal | about 0.25 kg | Close to goal weight, or very active people |
| 500 kcal | about 0.5 kg | Most adults |
| 750 kcal | about 0.7 kg | Higher body weight, with a doctor's okay |
| 1,000 kcal | about 0.9 kg | Only with medical supervision |
In the first week or two, weight often drops faster because the body lets go of stored carbohydrate and water. After that, expect the pace above.
How many calories to burn to lose 1 kg
About 7,700 kcal in total, from eating less, moving more or both. Exercise alone is slow: a brisk 45 minute walk burns roughly 200 to 250 kcal for a 70 kg adult, so 1 kg would need more than 30 such walks. Mixing a food deficit with daily walking works better.
See what different activities add on the calorie burn calculator and the walking calories page.
Ideal weight loss per month
Two to four kg a month is a realistic and safe target for most adults with weight to lose. Faster loss usually means more muscle loss, more hunger and a greater chance of regaining. Set a first goal of 5 percent of your current weight. That alone lowers blood pressure and blood sugar for many people.
Making a deficit easier to live with
- Fill half the plate with vegetables and salad at lunch and dinner.
- Eat protein at every meal; the protein calculator sets a gram target.
- Cut liquid calories first: sugary tea, cold drinks, juices and sweet lassi.
- Keep fried snacks and sweets for planned occasions rather than daily.
- Plan a breakfast with protein, such as besan chilla, eggs, poha with peanuts or curd with fruit, and a lighter dinner with dal, sabzi and one or two roti.
- Sleep well. Tired people eat more.
Count what you eat for a couple of weeks with the food calorie tool to learn where your calories come from.
When to stop and get help
Stop and see a doctor if you feel dizzy, faint, have heart palpitations, lose your period, or find yourself bingeing. Do not diet during pregnancy. People with diabetes on insulin or tablets must speak to their doctor before cutting calories, because doses may need to change.
If your loss stalls for more than three weeks, recheck your intake and activity first. A plateau is normal after several months; a short break at maintenance often helps.
Frequently asked questions
How many calories should I eat to lose weight?
About 300 to 500 kcal less than your maintenance calories. For many women that lands between 1,300 and 1,700 kcal, and for many men between 1,700 and 2,200 kcal.
How much calorie deficit to lose 1 kg a week?
About 1,100 kcal a day, which is too much for most people without supervision. A deficit of 500 kcal for about 0.5 kg a week is safer.
How many calories should be burned to lose 1 kg?
Roughly 7,700 kcal in total. Spread over two weeks, that is a gap of 550 kcal a day.
Is a calorie deficit calculator accurate?
It gives a good starting estimate. Weigh yourself regularly, then nudge the target 100 to 200 kcal up or down if progress is too fast or too slow.
Can I lose weight without counting calories?
Yes. Smaller portions, more protein and vegetables, fewer sweet drinks and more walking create a deficit too. Counting simply makes it easier to see.
What is a safe calorie deficit for women?
Usually 300 to 500 kcal a day, keeping intake above about 1,200 kcal. Take it slower if you are close to your goal weight.
Sources
- Mifflin St Jeor equation
- Energy content of body fat used in clinical nutrition