5 Most accurate weight loss calculators

5 Most accurate weight loss calculators

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Working out and eating right is all well and good, but do you find your progress is lagging somewhere?

There are those last few pounds you’re struggling to get rid of?

Maybe you know you need a little extra help but not quite prepared to fork out for a personal trainer or nutritionist?

Fair enough too!

Finding a good weight loss calculator could just be the key to solving those problems holding you back from achieving greatness!

The issue really could be that you’re consuming more calories than you’re TDEE (total daily energy expenditure), or the amount of calories you’re burning daily.

Ac accurate weight loss calculator can help you get to the root of your problem and finally you can drop those last few pounds.

Most accurate weight loss calculators

How do weight loss calculators work?

Most weight loss calculators are based around a formula which calculates exactly how many calories your body beds to function. 

This is known as Basal Metabolic Rate (BMR).

Often weight loss calculators aren’t accurate and and can provide you with wrong information.

Some don’t include all the variables needed to tell you how many calories you should eat to lose weight.

Mathematical formulas used in weight loss calculators

The Harris-Benedict formula was one of the first formulas used to calculate basal metabolic rate (BMR), the amount of energy expended each day at rest.

This was revised in 1984 more and was used up until 1990, when the Mifflin-St Jeor formula was introduced.

The Mifflin-St Jeor formula also calculates BMR, but has been shown to be more accurate than Harry-Benedicts revised formula.

The there is The Katch-McArdle Formula. This is slightly different in that it calculates resting daily energy expenditure (RDEE), which takes lean body mass into account. 

Neither the Mifflin-St Jeor nor the Harris-Benedict formulas do this.

Out of the three formulas, the Mifflin-St Jeor Equation is considered the most accurate for calculating BMR.

But the Katch-McArdle Formula can be more accurate for people who are leaner and know their body fat percentage.

The science behind weight loss calculators gets quite intricate, so i’ll try and out it as simple as possible to understand.

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    Weight loss calculators take into account weight, age, gender and height, and will give accurate results based on a combination of these. 

    It will factor in your lifestyle, whether you are sedentary, moderately active or highly active.

    This is the point where weight loss calculators can vary in terms of accuracy. 

    This is what makes some calculators better than others, and why I have done some research to find the most accurate weight loss calculators out there.


    Lets say you have two women who are the same weight, age and height who want to lose 30LB.

    This alone doesn’t mean they require the same amount of calories per day to lose the same amount of weight.

    One of the women might be a couch potato and does little to no exercise, and the other might go for a 5km walk each day.

    There are many things taken into account to accurately calculate how many calories are required to successfully lose weight. 

    It can be quite overwhelming to know which weight loss calculators are accurate, this is why I have done the research for you and come up with 5 of the most accurate calculators.

    5 Most accurate weight loss calculators

    This body weight planner was created by Kevin Hall, a scientists at the NIH.

    This planner is used by scientists at the National Institute of Health so this is one of your most accurate weight loss calculators ever made.

    Weight loss calculator
    Most accurate weight loss calculator
    Weight loss calculator

    The Body Weight Planner allows users to make personalized calorie and physical activity plans to reach a goal weight within a specific time period and to maintain it afterwards.

    This is a highly scientific designed calculator that encourages people to take control of their own health and educate them.

    It begins by calculating your BMR.

    Then you need to decide your goal weight, your desired time to reach this weight and the strategies you will implement to achieve this.

    It provides you with how many calories you need to maintain your current weight, how many you need to reach your goal, and how many to maintain the weight long term.


    This is a slightly more basic weight loss calculator, designed more for people who really just want to know how many calories they need to consume each day to reach their desired weight.

    It also provides some extra guidelines for gaining or losing weight.

    Body weight calculator
    Body weight calculator

    This Calorie Calculator is based on a number of equations. 

    • Mifflin-St Jeor Equation
    • Revised Harris-Benedict Equation
    • Katch-McArdle Formula

    The results are based on an estimated average.

    The value obtained from these equations is the estimated number of calories a person can consume in a day to maintain their body-weight, assuming they remain at rest.

    This value is multiplied by an activity factor, dependent on a person’s typical levels of exercise, in order to obtain a more realistic value for maintaining body-weight (since people are less likely to be at rest throughout the course of an entire day).

    While losing weight involves many variables that change from person to person, there is still a core science that can be the basis behind planning a weight loss strategy. 

    The widely-accepted science behind the weight loss calculator is:

    • One pound of mostly-fat body weight is the equivalent of 3,500 calories of either food or exercise.
    • The appropriate amount of calories to cut from your diet is between 20% and 40% of your normal calorie requirement. See the CDC.
    • Moderate exercise is considered to be 4.5 METs. (A MET is a rate of energy expenditure, similar to watts.) Vigorous exercise is 7 METs. Calorie consumption is: 1 calorie (technically, kilocalorie) per kilogram body weight per hour per MET.
    Lifespan weight loss calculator
    Life Span weight loss calculator

    This is a very intricate and effective weight loss calculator that can help your goals faster.

    The TDEE (Total Daily Energy Expenditure) is a good indicator of how many calories a person must consume in order to maintain his or her current weight. 

    This important number is dependent on a person’s basal metabolic rate and his or her activity level.

    They have a new and improved version of this calculator. They claim that it is extremely accurate, one of the best around.

    Some of the features:

    • Body Mass Index (BMI)
    • Maximum Genetic Muscular Potential – an estimate of how much muscle you can gain naturally without the use of steroids.
    • Maximum Fat Metabolism – an estimate of the maximum sustainable deficit you can be at without sacrificing lean body mass. (only visible if your goal is “weight loss” and choose “lean mass formula”)
    • Better explanations and Improved handling of Activity and Exercise Factor.
    • Refactored code – now performs more smoothly, especially in mobile devices. And looks better. 
    Damn ripped body weight calculator
    Damn ripped body weight calculator

    This easy to use calculator figures it all out for you, just type the details in and you’re away.

    It considers how active you are throughout the day by giving you five levels to choose from.

    This calculator also has a macro calculator function to help you work out the adjustments you need to make with your diet.

    As well as calculating your calories, it shows you what you can the percentage of fat, protein, and carbs you should consume. This is dependent on your current diet- high carb diet , low carb diet or keto diet.

    This highly advanced 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 your metabolism and gives a far more accurate calculation on how hard you’ll have to work and how long it may take to reach your goals. 

    Weight loss calculator
    Weight loss calculator
    Most accurate weight loss calculator
    Most accurate weight loss calculator
    Best weight loss calculator

    Precision Nutrition’s weight loss calculator makes easier to set appropriate behavior goals, and gives you a more realistic view of what you potential progress could look like.


    Weight loss calculators can definitely make dieting far easier by providing you with more accurate, scientifically based information that can speed up your weight loss journey.

    Weight loss calculators are heavily based on calories in vs calories out, so tracking calories is a must when using a weight loss calculator.

    An easy alternative to using a weight loss calculator and hvaing to track calories in order to lose weight is a diet that requires zero calorie counting. 

    The 21- Day Weight Loss Plan 

    requires absolutely no calorie counting and goes far beyond a 21 day weight loss diet plan.

    With the 21 day weight loss plan you will learn how to maintain weight loss long term.

    You will not be deprived of carbs fats and protein either. These are the main macronutrients your body needs to maintain optimal daily functions.

    To find out more about the diet plan or to get started you can check it out below.

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