When you’re trying to lose weight, the formula is simple — the number of calories you burn has to be greater than the number of calories you take in. Despite the promises of magic weight-loss pills and diets telling you to just avoid carbs and watch the pounds melt off, nutrition experts say plain old calorie counting is the best way to shed the pounds.

“Look at counting calories like spending money,” says Michael Nusbaum, medical director of the Obesity Treatment Centers of New Jersey. “You’re on a budget, so eat wisely.”

[See: U.S. News Best Weight-Loss Diets.]

So how do you know how many calories to budget? Start by figuring out your basal metabolic rate, or BMR, which is a measure of how many calories your body burns throughout the normal course of a day. From there, you’ll need to figure out how active you are and multiply your BMR by a set number, which is based on your amount of physical activity, to determine how many calories you can consume per day.

One pound of fat is 3,500 calories, so to lose one pound per week, you need to remove that many calories from your diet. Spread out over seven days, that means subtracting 500 from the number you got above and sticking to it. “You need to think of your food intake as the same way you think of filling up the gas tank in your car,” Nusbaum says. “You’re not going to overfill your gas tank, so why give yourself more calories than your body needs?”

You can track the number of calories you’ve had over the course of a day using a variety of apps and websites such as MyFitnessPal or CalorieKing, which usually have the calorie content of your favorite foods already built in.

[Read: How to Turn Your Phone Into the Ultimate Weight-Loss Tool.]

Although your BMR should be fairly accurate, it doesn’t take into account everyone’s individual metabolism, says Christine Palumbo, a registered dietitian and adjunct faculty member at Benedictine University in Illinois. “Everyone is different,” she says. “Some people have faster or slower metabolisms, so if you’re not noticing the weight loss after a few weeks or months, you might have to adjust it.”

One easy way to cut down on your daily calories is to cut out soda and sugar-laden coffee. “Drink calories count,” Palumbo says. “Your morning coffee adds calories, especially when you add in lots of sugar and milk, but we never think of it that way.”

[Read: Eat Your Calories, Don’t Drink Them.]

Replace all your drinks with water, Nusbaum says, and you’ll not only find it much easier to stay within your calorie budget, but that you’ll lose weight easier. “Your body needs water to burn fat,” he says. “You’ll notice that the weight loss comes easier when you drink a lot of water.”

And the old adage about drinking eight glasses every day? “That should be the minimum you drink,” he says. “More is always better.”

[Read: How to Drink More Water Each Day.]

In addition, cooking at home helps you know what goes into your food, which not only provides a more accurate picture of your dinner’s caloric content, but it’s healthier to boot. “When you go out to a restaurant, the food is designed to taste good, not be good for you,” Nusbaum says. “The problem is that you’re getting more fat and sodium than you need.”

Even though all calories are equal, Nusbaum says, what you eat still makes a big difference not only for your health, but for sticking to your calorie budget as well. “Fruits and vegetables are low in calories but keep you full,” he says. “Plus they’re good for you, so try and get as much of your calories as you can from those.”

You can still have carbs and ice cream and whatever else you want when you’re counting, as long as you stay within your allotment. However, you’ll quickly find that indulging frequently will leave you with many fewer calories throughout the rest of your day. “Go for things like lean protein over fatty foods,” Nusbaum says. “Fat has double the amount of calories as protein in the same serving size.”

Exercise is important as well — not only does it speed up your metabolism, but the calories you burn can actually be added onto the number you can eat that day. For example, if you’re sticking to a 1,500 calorie budget, a workout where you burn 300 calories would allow you to eat 1,800 calories that day and still stick to your daily allotment.

[Read: Diet vs. Exercise: A Healthy Habit Showdown.]

The key to sticking with calorie counting is being meticulous about logging everything you eat, which for some people can seem tedious, Palumbo says. “It’s just one more task to add to our busy schedule,” she says. “The people who seem to be very successful at calorie counting tend to have a little essence of OCD in them.”

It’s also important not to get discouraged. “You didn’t put on all this excess weight overnight, so you’re not going to lose it that fast either,” Palumbo says. “It’s going to take time and effort, but in the end, it’ll be worth all the hard work.”

[Diet Success Videos: How One Woman Lost 90 Pounds.]

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How to Count Calories originally appeared on usnews.com