Last Updated on November 7, 2022 by
One fact is indisputable: every overweight person had to start out skinny. How did they do it? Most likely, these skinny people followed a low carbohydrate diet. For example, if you want to reduce your weight by 10 pounds in two months, you will need to reduce your daily calorie intake by 500 calories per day. How can you calculate that? Let’s use the low carb diet calculator for this purpose.
Calculating your macros for weight loss is one of the most important things to do as a low carber. I’ve put together this low carb calculator to help you calculate your macros without much effort. Not only will it calculate your macros but it will break down how they split up between protein, carbs and fats”
Low Carb Calculator For Weight Loss
How to calculate macros: the best low carb & keto macro calculator for weight loss! This FREE macro calculator lets you calculate macros for both low carb and keto diets.

This free keto macro calculator will help you figure out how much fat, protein, and carbs you should eat on the keto diet for your size.

In today’s post, I am going to share everything you need to know about calculating your macros when starting a low carb diet and how to use a free keto macro calculator to do just that.
???? What Are Macros?
The word macros is short for macronutrients. There are three categories of macros that people need to track if they want to stay in ketosis – protein, fat, carbs.
Here is a little introduction to these three macros.
- Carbohydrates – Includes sugars, starches, and fibers. They are found in grains, starchy vegetables, beans, dairy products, and fruit.
- Fats – These have the most calories of all the macronutrients. It provides your body energy. Healthy fats are found in foods like oils, butter, avocado, fish, and nuts.
- Protein – Proteins are the building blocks of muscles. How much protein you need depends on your body’s composition, your age, and your overall health. Protein-rich foods include eggs, meat, beans, and tofu.
???? Calculating Macros On The Keto Diet
There are lots of factors that change how much of each macro your body needs.
- Do you want to lose weight?
- Do you need to just maintain your weight?
- What is your age and activity level?
While it’s possible to take all of this into account and calculate your macros on your own, I took all the hard work out of it! The easiest way to figure out how many macros you need is to use my keto macro calculator.

FAT
Fats are the densest form of energy, meaning that it takes more space to store fat than either protein or carbohydrates. You can get fat from various animal and plant sources. Some of the most common types of fat on a keto diet are dairy, meat, and seafood, chocolate, olives, oils, etc.
PROTEIN
Protein provides the body with some of the essential amino acids that it can’t make on its own, directly or indirectly. It is your protein intake that helps you to build muscle and retain muscle mass, slow down the digestion of other nutrients (which prevents blood sugar spikes), and allows your body to utilize glucose as fuel.
Protein sources include animal and plant sources. Meat and dairy are the obvious choices on an omnivore diet but since we’re plant-based, most of our protein comes from soy products like tofu, nuts and seeds, as well as protein powders and leafy greens.
CARBOHYDRATES
Carbohydrates are your body’s preferred form of energy because it is less dense than fat (it takes more space to store) and because it is easily accessible in the human body. When you eat carbohydrates – bread, potatoes, pasta etc. – your body stores them in the liver and muscles (your muscles essentially store glucose which you can use to fuel your brain).
Most plant-based foods contain carbohydrates, but some like leafy greens are also high in fiber. The point of eating low carbs is to get the body used to using fats for energy rather than glucose – this process is called ketosis and in the end, is what allows you to burn fat instead of using carbs for fuel. It’s especially helpful in lowering insulin and glucose which makes weight loss easier for some.
A NOTE ON FIBER
Fiber is a non-digestible carbohydrate that comes from plants and is excreted by your body without being broken down. There are two types: soluble and insoluble, both of which provide health benefits such as preventing constipation and regulating blood glucose levels. To get net carbs, you simply subtract the amount of fiber from the total carbohydrates.

Want MORE keto recipes?
Get updates on the latest recipes and more from Low Carb Yum straight to your inbox. IMPORTANT: Please check SPAM folder if email is not received.SUBSCRIBEI consent to receiving emails and personalized ads.
After you figure out how many macros you need, you can start tracking them in your meals.
???? Instructions
Here’s how to use the keto calculator to determine your optimum daily macros:
First, choose which measurements you want – metric or US customary. Then, fill out all the fields as accurately as you can.
After all the fields are completely filled out, the results will automatically populate.
There are four different amounts of macros that will populate at the bottom of the calculator – maintenance (if you want to maintain weight) and three weight loss options. Choose the one that most closely resembles your weight loss goals.
???? Free Keto Macros Calculator
Here’s the free keto macros calculator. Fill it in and discover exactly how many macros you should be eating every day.
Units Metric US Customary
Gender Female Male
Ageyears
WeightKg
Heightmeters (e.g. 1.76 meters = 176 cm)
Activity Level Sedentary Lightly active Moderately active Very active Athlete/Bodybuilder
Body fat%
Net carbsgrams
Specify the amount of daily net carbs you’d like to consume. Typically, 20-30 grams is recommended to start with.
Results
Maintenance
Maintenance level is the level at which your weight remains stable.
Your BMR is: | 1516 | kcal |
Calories to consume: | 1834 | kcal |
Your fat intake should be: | 158 | grams |
Net Carbs | Protein | Fat | |||
25 | grams | 78 | grams | 158 | grams |
100 | kcal | 312 | kcal | 1422 | kcal |
5 | % | 17 | % | 78 | % |
Goal
Weight loss Weight gain Custom
Below is a range of calorie deficits to help you lose weight. For best results, it is recommended that you opt for a moderate calorie deficit of 10-20%.
Small calorie deficit (11%)
Calories to consume: | 1633 | kcal |
Your fat intake should be: | 136 | grams |
Net Carbs | Protein | Fat | |||
25 | grams | 78 | grams | 136 | grams |
100 | kcal | 312 | kcal | 1221 | kcal |
6 | % | 19 | % | 75 | % |
Moderate calorie deficit (22%)
Calories to consume: | 1431 | kcal |
Your fat intake should be: | 113 | grams |
Net Carbs | Protein | Fat | |||
25 | grams | 78 | grams | 113 | grams |
100 | kcal | 312 | kcal | 1019 | kcal |
7 | % | 22 | % | 71 | % |
Calories to consume: | 1229 | kcal |
Your fat intake should be: | 91 | grams |
Net Carbs | Protein | Fat | |||
25 | grams | 78 | grams | 91 | grams |
100 | kcal | 312 | kcal | 817 | kcal |
8 | % | 25 | % | 67 | % |
The Low Carb & Keto Macro Calculator will help you figure out how much of each macronutrient to eat to reach your goals.
What makes this macro calculator unique is that you can use it for both a low carb diet and a keto diet. Along with entering your information, you can select the diet type you want to follow, and even customize it to fit your needs.
Get my keto cheat sheet here to help you stick to your macros!
HOW TO CALCULATE MACROS
Just fill out the form below and hit “Calculate Macros”!
THE BEST LOW CARB & KETO MACRO CALCULATOR
Unit of Measurement Gender
doneFemale
doneMaleAgeyearsHeight feetinches
WeightpoundsBody Fat Percentage28%Activity Level Sedentary Lightly Active Moderately Active Very Active Athlete/Body Builder Diet Type
doneKetogenic
doneLow CarbNet CarbsgramsProtein Ratio0.6Goal
doneLose Fat
doneMaintain Weight
doneGain MuscleDeficit15%
I HAVE QUESTIONS ABOUT THE LOW CARB & KETO MACRO CALCULATOR!
Check the FAQ below first. Then, if you still have a question, you can leave a comment at the bottom of this page. We cannot offer 1-on-1 support here, but I’m happy to answer general questions.
WHY DO I NEED TO CALCULATE MY MACROS?
A low carb or keto lifestyle can be life changing, and has huge benefits. But, everyone’s requirements are different.
This low carb and keto macro calculator will define for you how much you should be eating, and the answer is tailored just for you.
CAN’T I JUST EAT LOW CARB OR KETO FOODS?
Yes, you can, and many people have had success in doing so. This is sometimes called “lazy keto” or “lazy low carb” – not because you are lazy, but because it’s much easier to just eat the right foods than to count everything.
But, if you are just starting out, have not achieved desired results by just eating low carb foods, are already relatively close to goal weight, or want to follow a more strict low carb or keto diet, then getting your exact macro requirements will be a huge help.
WHAT IS THE DIFFERENCE BETWEEN LOW CARB AND KETO?
The main difference between low carb and keto is that the primary goal of keto is to get into a state of ketosis. This happens when the body switches from burning glucose for fuel to burning fat for fuel, and ketones are the byproduct of this metabolism.
From the perspective of what you eat, the difference between low carb and keto is the distribution of macronutrients and how they are calculated. You can read a bit more about that in the next question below.
HOW IS THE MACRO CALCULATOR DIFFERENT FOR A LOW CARB VERSUS KETO DIET?
Your calorie needs are the same whether you follow a low carb diet or keto diet. But, the macronutrients will be different.
For a low carb diet, the low carb macro calculator will determine your macros by taking recommended percentages of fat, protein and carbohydrates. These are based on percentage of total calories, and you can adjust the percentages if you want to.
For a keto diet, the low carb macro calculator first sets your net carbs to an absolute amount. You can change this, but the default is 25 grams. Then, it calculates your protein requirement, which is based on your lean body mass and a protein ratio based on your activity level. The remaining calories come from fat.
WHICH OPTIONS SHOULD I SELECT FOR LOW CARB? WHAT OPTIONS FOR KETO?
The Macro Calculator will automatically pre-fill the recommended values for low carb or keto diets based on your inputs and activity level. If you want to, you can modify them to suit your needs.
For a low carb diet, here are the recommended macro percentages:
- Fat: 40 to 70%
- Protein: 15 to 30%
- Net carbs: 15 to 30%
For a keto diet, if you are sedentary this is recommended:
- 25g net carbs – typically between 20g and 30g is a good starting point
- 0.6 protein ratio – this will be higher if you are active
HOW ARE MACROS CALCULATED? WHY DO YOU NEED ALL THIS INFORMATION? ARE YOU SURE THE CALCULATION IS RIGHT?
The calculator above does everything for you, so you don’t have to know how to calculate macros manually. If you want to know how it works or why we need the information, here is an overview…
The majority of information you need to enter is to find your Total Daily Energy Expenditure (TDEE), which is the number of calories you burn per day. This is determined by your gender, age, height, weight, and activity level.
We use the Mifflin-St. Jeor equation for calculating Basal Metabolic Rate (BMR), which is the number of calories you burn for basic, life-sustaining functions. This equation has been shown to be most accurate *.
Then, your activity level combined with BMR determines the TDEE.
Your body fat percentage is used to determine lean body mass, which affects how much protein you need.
We do not store or save any information you enter into the macro calculator.
The low carb and keto macro calculator provides accurate macros as long as you enter the information correctly, in the right units.
WHAT IS THE PROTEIN RATIO?
The protein ratio determines the number of grams of protein you should eat per day. It’s measured as # of grams per kilogram of LEAN body weight (meaning everything except fat).
Protein is a goal on keto, meaning you should strive to meet your daily protein goal, but not exceed it. Protein is made up of amino acids, which are the building blocks of cells. Amino acids help us maintain or build muscle, and are crucial for hundreds of cell processes we need to live.
Why does protein ratio matter? Because too much protein can kick you out of ketosis (and is not good for your kidneys), but not enough protein can cause you to lose muscle.
Don’t worry, you don’t have to figure out your own necessary protein ratio unless you want to. The amount of protein per pound of lean body mass that you need depends on how active you are, and the keto macro calculator above will automatically set the best protein ratio for you, based on the activity level you select.
Here are general guidelines for protein ratio based on activity level:
- Sedentary – 0.6g to 0.8g protein per pound of lean body mass
- Lightly Active – 0.7g to 0.9g protein per pound of lean body mass
- Moderately Active – 0.8g to 1g protein per pound of lean body mass
- Very Active – 1.0 to 1.2g protein per pound of lean body mass
- Athlete / Body Builder – 1.2g protein per pound of lean body mass
Notice that each has a range, and you can experiment with what feels comfortable for you and gets you the results you want.
What about your lean body mass that is mentioned several times above – how do you figure out what that is? This is the weight of everything in your body that isn’t fat. The calculator will automatically figure this out based on the body fat % that you enter, which you can estimate using the chart below. You could also manually calculate it if you’re curious:
Lean Body Mass = Your Total Weight – (Your Total Weight X Your Body Fat %)
HOW DO I GET MY BODY FAT PERCENTAGE?
Body fat percentage can be calculated using various scanners (like a DEXA scan at a gym or doctor’s office) for the highest accuracy.
If you want to measure at home, the easiest way is to use skin calipers.
If you don’t have these either, compare how you look visually to these to get a very general estimate:
WHAT’S THE BEST WAY TO MEET THE MACROS I GOT FROM THIS MACRO CALCULATOR?
You can get a full low carb keto food list here, which says how many net carbs in each food.
That’s a good starting point in choosing which foods are good for a low carb or keto diet. Beyond that, a tracker app can help.
WHAT DOES THE “DEFICIT” OR “GAIN” IN THE MACRO CALCULATOR MEAN?
This is the percentage of calories that you want to go over or under what you’d need to maintain your weight.
If you select Lose Fat (lose weight) as your goal, then you can select the Deficit. The macro calculator will then recommend that you eat this percentage fewer calories than you need. Eating less calories than you need will result in weight loss. For example, if you select 15% as the deficit, the calculator will output 15% fewer calories than your body needs for maintenance.
The recommended Deficit for losing weight is 10-20%, because more than that may result in nutrient deficiencies, difficulty sticking to the plan, and/or muscle loss.
If you select Gain Muscle as your goal, then you can select the Gain (surplus). The macro calculator will then recommend that you eat this percentage more calories than you need. Eating more calories than you need will result in weight gain, which will be in the form of muscle if you do weight training. For example, if you select 10% as the gain, the calculator will output 10% more calories than your body needs for maintenance.