Calorie Deficit Calculator: How Many Calories to Lose Weight
Find your daily calorie target for weight loss, how big your deficit should be and the date you will hit your goal weight, with built-in safety limits.
What is a calorie deficit?
A calorie deficit means eating fewer calories than your body burns in a day. Your body still needs that missing energy, so it takes it from storage, mostly body fat. Keep that up for weeks and the number on the scale goes down.
The amount your body burns is your TDEE, your total daily energy expenditure. This calculator works it out first with the Mifflin-St Jeor equation, then subtracts the right deficit for the pace you choose. If you just want your maintenance number, use our TDEE calculator.
How big should your calorie deficit be?
Bigger deficits give faster results, but they also make you hungrier, more tired and more likely to lose muscle. For most people, losing about 0.5% to 1% of body weight a week is the sweet spot.
Deficit size vs your body weight
| Your weight | 1% a week | Max daily deficit |
|---|---|---|
| 130 lb (59 kg) | 1.3 lb (0.6 kg) | about 650 kcal |
| 160 lb (73 kg) | 1.6 lb (0.7 kg) | about 800 kcal |
| 200 lb (91 kg) | 2 lb (0.9 kg) | about 1,000 kcal |
| 250 lb (113 kg) | 2.5 lb (1.1 kg) | about 1,000 kcal (cap) |
The minimum calories you should eat
Very low intakes make it hard to get enough protein, vitamins and minerals, and they are rarely sustainable. That is why our calculator never recommends going below these floors.
Women
General minimum for adult women without medical supervision.
Men
General minimum for adult men without medical supervision.
Talk to a doctor before dieting if you
- are pregnant or breastfeeding (see our breastfeeding calorie calculator instead)
- are under 18
- have diabetes, heart, kidney or thyroid disease, or take medication that affects appetite or blood sugar
- have, or have had, an eating disorder
Why weight loss slows down over time
Most calculators use the old “3,500 calories = 1 lb” rule and assume you will lose the same amount every week. Real bodies don’t work that way, which is why our goal date is recalculated week by week.
As you lose weight, your TDEE drops because there is less of you to move and maintain. Your body may also cut back a little on unconscious movement. That is normal. Recalculate every 10 lb (5 kg), and if progress stalls for three weeks or more, read our guide on why you might not be losing weight in a deficit.
6 ways to stick to your calorie deficit
Protein keeps you full and protects muscle. Use our protein calculator to find your target.
Vegetables, fruit, beans and whole grains add volume for very few calories.
Extra steps widen your deficit without making you hungrier the way hard cardio can.
Logging food, even roughly, shows where hidden calories come from.
Short sleep raises hunger hormones and makes cravings harder to ignore.
Split your calories into protein, carbs and fat with our macro calculator.
Should you create the deficit with diet or exercise?
Mostly from food
Cutting 300–500 calories from what you eat is the most reliable way to create a deficit. A single snack or sugary drink can be 300 calories; burning that off takes about 45 minutes of brisk walking.
Exercise for the rest
Exercise protects muscle, improves health and adds a little to your deficit. Strength training is especially useful while dieting. Just don’t add workout calories from your watch on top of a TDEE that already includes them.
Calorie deficit FAQs
How many calories should I eat to lose weight?
Start with your TDEE and subtract about 500 calories. For most people that leads to roughly 1 lb (0.45 kg) of weight loss a week. Don’t go below about 1,200 calories for women or 1,500 for men without medical supervision.
Is a 1,000 calorie deficit safe?
It can be for people with a lot of weight to lose, as long as your intake stays above the safe minimums and you eat enough protein. For people who are already close to a healthy weight, it usually causes too much muscle loss and hunger.
How long does it take to see results in a calorie deficit?
The scale often drops in the first week, mostly from water. Visible fat loss usually shows after 3 to 4 weeks of consistent dieting. Compare weekly average weights rather than single days.
Can I lose weight without counting calories?
Yes. Eating more protein and vegetables, cutting sugary drinks and alcohol, and walking more often creates a deficit on its own. Counting just makes it easier to know you are in one.
Why is my calorie deficit not working?
Most often it is underestimated food intake, an activity level set too high, or water retention hiding fat loss. Track carefully for 2 to 3 weeks before cutting calories further.
Does a calorie deficit burn muscle?
A small amount of muscle can be lost in any deficit, but strength training, enough protein and a moderate pace keep it to a minimum.