Want to know the number of calories you should eat to lose weight? We’ve made it easy. Just click the “Get Started” button below and enter your information.
(Plus, once we calculate your calorie and macronutrient needs, we’ll send you a free, personalized nutrition plan for achieving the results you want.)
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Why This Weight Loss Calculator Is Special
One of the most common questions Precision Nutrition certified nutrition coaches get from their new clients:
“I’ve been tracking my calories in and calories out religiously… but I’m not losing as much body fat as I should. Why isn’t this working?!?”
Yes, conventional wisdom states that reducing your calorie intake (or increasing the amount of calories burned) by 500 calories a day should lead to about 1 pound of fat loss per week. (Math: A daily calorie deficit of 500 calories x 7 days = a total calorie deficit of 3500 calories per week = 1 pound.)
But that conventional wisdom is wrong. As discussed in this article all about the myth of metabolic damage, your metabolism is adaptive. As you eat less, your metabolic rate slows, throwing off common assumptions about calorie balance.
This excellent weight loss calculator—based on the NIH Body Weight Planner and adapted from research collected at the National Institute of Diabetes and Digestive and Kidney Diseases—takes into account the adaptive nature of metabolism and gives more accurate information on how many calories you’ll need to eat (and how long it may take) to reach your weight loss goals.
Advantages of this Weight Loss Calculator
To understand why this weight loss calculator is so helpful, let’s use an example client: Vanessa.
She’s 40 years old, 5’ 6” tall, weighs 185 pounds, has a very low level of activity at work, and a moderate level of exercise activity.
Based on this information (including her estimated basal metabolic rate, or BMR), our calorie calculator has determined that she needs around 2,445 calories per day to maintain her weight.
Let’s say Vanessa wants to lose 40 pounds (so a goal weight of 145 pounds) in a sustainable way over the course of the next year, without doing any additional exercise.
The calorie calculator suggests she’ll need to reduce her food intake to around 1,770 calories per day. That results in a calorie deficit of 675 calories. (In other words, it’s 675 calories lower than the number of calories required to maintain her weight.)
If you do conventional calorie math, these numbers don’t make sense.
A daily calorie deficit of 675 calories would lead to a deficit of 246,375 calories over a full year. (Math: 675 calorie deficit x 365 days = 246,375 calories.)
This would, theoretically, lead to a 70-pound weight loss for Vanessa. (Math: 246,375 calorie deficit / 3,500 calories in 1 pound of body fat = 70 pounds lost.)
But the body doesn’t work that way. Instead, Vanessa would lose only about 40 pounds. (Which is still awesome, obviously.)
Why this very large disparity?
As mentioned above, your metabolic rate adjusts as you eat less and lose weight. And conventional math doesn’t take this complex nature of human metabolism into account.
That’s why it’s important to make sure your expectations about weight loss and body fat change are in line with how your body actually works.
This calorie calculator helps with that. It makes it easier to set appropriate behavior goals and gives you a more realistic view of what your potential progress could look like.
More Benefits of this Weight Loss Calculator
The Precision Nutrition Weight Loss Calculator is special for other reasons, too.
It not only takes into account your personal details (height, current weight, age, sex), your estimated basal metabolic rate (or BMR), physical activity levels, and the amount of weight you want to lose, but also allows you to:
- Choose your dietary preference. (You can select from Paleo, keto, vegetarian, fully plant-based/vegan, Mediterranean, and of course, “anything”)
- Adjust your macronutrient preference. (If desired, you can change the amount of carbs, fat, or protein to better fit your needs.)
- Use “hand portions” to easily track your food intake. (More on this below.)
The Weight Loss Calculator takes all this information and uses it to estimate your calorie and macronutrient needs so you can lose weight. It also automatically converts those numbers into food portions that are equivalent to parts of your hands. (For example: your palm, fist, thumb, and cupped hand.)
The benefit: This allows you to easily know how much to eat to lose weight—but without needing to weigh and measure your food, or log the details of every meal into a food tracking app.
Instead, you can use our hand portion tracking system to take the hassle out of calorie and macro tracking—and still achieve your targets. (And, by the way, if you want to gain weight, it can give you the hand portions for that, too.)
Once the Weight Loss Calculator runs your numbers, it’ll generate a FREE nutrition plan that’s personalized for your body, preferences, and weight loss goals and will show you exactly what to do.
Ready to get started? Enter your information in the Weight Loss Calculator above, and we’ll take care of the rest.
If you’re a coach, or you want to be…
You can help people build sustainable nutrition and lifestyle habits that will significantly improve their physical and mental health—while you make a great living doing what you love. We’ll show you how.
If you’d like to learn more, consider the PN Level 1 Nutrition Coaching Certification.