How Many Calories to Lose Weight? Find Your Number

How many calories to lose weight is really two questions stacked on each other. The first is what your body burns in an ordinary day, which you can estimate in about a minute. The second is how far below that you should eat, which is where most advice goes wrong by promising a rate almost nobody hits. This guide covers both, hands you a starting target you can use today, and is straight about the part where the arithmetic stops matching the scale.

So how many calories should you eat to lose weight?

Take the number of calories that hold your weight steady and subtract 250 to 500 a day. For most adults that lands somewhere between about 1,300 and 2,200 calories, and where you fall inside that range depends mostly on how big you are and how much you move.

There is no single correct number, and any article that gives you one without asking your height, weight, age and activity is guessing. A sedentary 150 pound woman and a lightly active 210 pound man can differ by more than a thousand calories a day at maintenance, so they cannot possibly share a target.

On the goal itself, the National Institute of Diabetes and Digestive and Kidney Diseases suggests losing 5 percent of your body weight over about six months as a good opening target. At 200 pounds that is 10 pounds, which sounds unambitious and is exactly why it tends to work.

How do you find your maintenance calories?

Estimate your resting burn, then multiply by an activity factor. The most validated starting point is the Mifflin-St Jeor equation, published in a 1990 study of hundreds of healthy adults and later found more likely than the alternatives to land within 10 percent of measured resting metabolic rate.

The equation, in one line

Weight in kilograms, height in centimeters, age in years:

• Men: (10 x weight) + (6.25 x height) minus (5 x age) + 5
• Women: (10 x weight) + (6.25 x height) minus (5 x age) minus 161

Multiply the result by 1.2 if you are sedentary, 1.375 if you exercise lightly a few days a week, 1.55 if you train most days. If you would rather not do the arithmetic, our TDEE calculator runs the same equation and two others in your browser. Either way, the usual failure here is the activity factor, not the equation: almost everyone rates themselves one level too high. A desk job plus three gym sessions is lightly active, not very active. When you are torn between two levels, take the lower one and let the scale argue with you later.

How big should the cut be?

Between 250 and 500 calories a day for most people, scaled to your size. The CDC notes that people who lose weight gradually, at about one to two pounds a week, are more likely to keep it off, and a useful way to scale that to your own body is to aim for roughly 0.5 to 1 percent of your bodyweight per week. A 250 pound person can comfortably run a larger deficit than a 140 pound person, in absolute calories and in pounds on the scale. As you get lighter, the sensible move is a smaller cut and a slower pace.

If you want the full walkthrough of building and living with that gap day to day, our calorie deficit diet guide covers it. This post stays on the number.

What does that look like in actual numbers?

Here are six ordinary profiles run through Mifflin-St Jeor and an activity factor, rounded to the nearest five calories. Find the row closest to you and treat it as a starting estimate, not a prescription.

Two things stand out. The spread between the first and fifth row is over a thousand calories a day, which is why generic targets fail so many people. And the smallest person in the table cannot take the biggest cut without eating too little, which is the trade-off nobody mentions when they hand out the 500 calorie rule.

Why does the 3,500 calorie rule overpredict your loss?

Because it assumes your body stays the same while you shrink, and it does not. The familiar rule says a pound of fat holds 3,500 calories, so a 500 calorie daily cut should give you a pound a week, forever. Run that forward and a year of dieting produces about 52 pounds. Almost nobody gets that, and the reason is not willpower.

As you lose weight there is less of you to carry around, so you burn less doing exactly the same things, and the deficit you started with quietly shrinks toward zero. Kevin Hall and Carson Chow of the NIH put it plainly in a 2013 letter titled Why is the 3,500 kcal per pound weight loss rule wrong? The most serious error, they wrote, is that the rule fails to account for the dynamic changes in energy balance that happen during the intervention itself. A 2014 analysis in the Journal of the Academy of Nutrition and Dietetics reached the same place, noting that static energy balance assumptions produce exaggerated weight-loss predictions with no plateau.

The replacement rule of thumb comes from Hall and colleagues in The Lancet in 2011: every permanent change of about 10 calories a day is worth roughly one pound of eventual body weight, with about half of that change arriving in the first year and 95 percent within three. Put your 500 calorie cut through it and the answer is about 50 pounds eventually, around 25 of them in year one. That is still a lot of weight. It is just not 52 pounds, and expecting the right figure is what stops people quitting at month five because the scale is only down fifteen.

A few practical things follow from that:

• Expect the fast start. The first two weeks usually move more than the model predicts, much of it water and gut contents rather than fat.
• Expect the slowdown. A plateau at month four is usually not a failure of discipline. It is what the model predicts.
• Recut occasionally. Recalculate maintenance every 10 to 15 pounds, because the number you started with no longer describes the body you have.

If your scale has stopped moving and you want the full list of reasons, we covered them in why the scale goes up in a calorie deficit.

How low is too low?

Below roughly 1,200 calories a day for women and 1,800 for men, getting enough vitamins and minerals becomes hard. That threshold comes from a 2025 joint advisory from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association and The Obesity Society, which flags insufficient intakes of essential micronutrients at energy intakes under those numbers. Treat it as a hard limit on how aggressive the cut can be.

Look back at the table. Two of those six rows fall under their floor at a 500 calorie cut. If yours does too, you have three honest options and one bad one:

1. Take the smaller cut. 250 calories a day, and accept that it will take longer.
2. Raise the other side. Add daily movement so maintenance goes up and the same target becomes a bigger gap.
3. Eat the floor deliberately. Sit at the threshold with protein and vegetables doing most of the work, and treat it as a phase rather than a lifestyle.
4. The bad one: go lower anyway, feel terrible, lose muscle along with fat, and quit in five weeks.

Very low intakes are not automatically dangerous, but they need medical supervision.

Can you lose weight faster by cutting more?

You can for a while, and it usually costs more than it buys. A larger deficit takes a bigger share of the loss out of muscle instead of fat, and it is harder to stay with.

The clearest illustration comes from a trial of elite athletes that ran two rates side by side. One group lost weight at about 0.7 percent of bodyweight a week, the other at 1.4 percent, both ate plenty of protein, and both finished having lost roughly the same 5.5 percent of their body weight. The slower group gained 2.1 percent lean body mass along the way. The faster group finished flat. Same number off the scale, different body underneath it. These were trained athletes on a supervised program, so the exact figures are not yours, but the direction is the useful part: the quicker you take it off, the less of it is fat.

Adherence pushes the same way. The reason authorities keep recommending one to two pounds a week is not caution for its own sake, it is that gradual losers are the ones still holding the result a year later. If you want to protect muscle while the deficit runs, the two levers that matter are eating enough protein and lifting something heavy twice a week. Our guide to how much protein you actually need has the numbers.

Should you eat back the calories you burn exercising?

Usually not all of them, for two separate reasons: the burn number is unreliable, and you may have already counted it.

Wearables are bad at this particular job. A Stanford evaluation of seven wrist-worn devices found that heart rate came in within an acceptable error range in most settings, but not one of the devices estimated energy expenditure within an acceptable range in any setting. Treadmill and cardio machine displays are no more trustworthy, and both err in the flattering direction.

The second problem is less obvious. If you chose an activity factor of 1.55 because you train five days a week, those sessions are already inside your maintenance number. Adding them again at the end of the day closes the gap you just spent ten minutes calculating.

The clean approach is to leave exercise out of the daily arithmetic entirely. Pick the activity factor that describes your normal week, eat the same target on training and rest days, and settle whether the estimate was right with two weeks of data. If you are training hard and genuinely underfueled, that shows up as losing faster than about 1 percent of bodyweight a week, which is a signal to eat more, not a reason to chase a tracker number.

How do you correct the number with your own data?

Every number above is an estimate built from population averages. Yours will be off by some amount, and the only way to find out by how much is to run it for two or three weeks and compare what happened to what was supposed to happen.

1. Log everything for 14 to 21 days at your starting target, including the weekend.
2. Weigh yourself most mornings and read the weekly average, never a single day. Daily weight moves several pounds on water alone.
3. Compare the two averages. Losing faster than about 1 percent of bodyweight a week means you can eat more. Losing nothing across three well-logged weeks means the target is 100 to 200 calories too high.
4. Adjust once, then wait. Change the target by 100 to 200 calories and give it another two weeks before touching it again.

The word doing the work in step one is honest. The classic New England Journal of Medicine study of people who believed they were diet resistant found they were underreporting what they ate by about 47 percent while overreporting activity. They were not lying. Cooking oil, drinks, the handful of something on the way past the counter: those are the calories that vanish from a log. If your data says the math is broken, the log is usually the thing to check first. Our guide to counting calories properly covers what tends to go missing.

Where Countwell fits

A target is only useful if you can see what you are eating against it. Countwell is a food log built for the meals that break tracking: restaurant plates get logged item by item rather than as one opaque total, a photo gives you a fast first estimate you can correct in a tap, and the numbers come from a live nutrition database (FatSecret) rather than a pile of user-submitted guesses. Set the number, log against it for three weeks, and let the trend tell you whether the estimate was any good.