Your Personal Fat Loss Calculator

This weight loss calculator for the ketogenic diet determines your optimal food intake for your personal weight loss goals on the ketogenic diet. Click for more!

A ketogenic diet is a high-fat, adequate-protein, low-carbohydrate diet. It has a lot of health advantages compared to the standard western diet. Most people do keto because of the weight loss, but it also has other health advantages like lowering risk for heart disease, diabetes, cancer, stroke, and much more.

James Hardiman has created a nice tutorial for this calculator, watch it here:

Enter Your Personal Data

To get your personal customized recommendations, please enter some data about yourself.

Female Male
kg weight ( lbs)
cm tall (' ")
Date of birth:

Determine Your Energy Expenditure

Given that data it is possible to calculate your Base Metabolic Rate (BMR). This site uses the Mifflin-St.Jeor-Formula which was found to be the most accurate in two studies.

  • kcal Base Metabolic Rate

The BMR resembles the resting metabolic rate. The real daily energy expenditure depends on how active you are on average. Based on that activity level your actual total daily energy expenditure (TDEE) can be calculated. This is the amount of calories you need to consume each day when you do not want to lose weight.

  • Sedentary. Typical desk job, little to no exercise.
    Lightly active. Walking around a good amount, retail jobs. 1–3 hours per week of light exercise.
    Moderately active. 3–5 hours a week, e.g. daily 15 minutes biking and 3 times heavy lifting per week.
    Very active. Construction workers, hard exercise 6–7 days per week
    Custom: kcal
  • kcal daily energy expenditure

How Much Body Fat do you Have?

Let's find out your body fat percentage. Based on your height and weight, your body fat percentage might be around %. The most accurate measurement would be a DEXA. Skin fold measurement with a good caliper is also pretty accurate. The easiest way is to just estimate it from some comparison pictures. More: 1, 2, 3, 4. You can also try this calculator but that can be inaccurate.

  • % Body fat

With % body fat you have kg (lbs) of lean body mass, and kg (lbs) of body fat. This includes about kg (lbs) of essential body fat that you must not lose.

Learn Your Optimal Macronutrient Ratio

Macronutrients are nutrients that provide energy for your body.

How Many Carbs Can I Eat?

Below 50g of net carbs each day is sufficient for most people to stay in ketosis. Make sure to get your carbs from vegetables (10-15g), nuts and seeds (5-10g), and fruits (5-10g). Keep in mind that in Europe food labels generally show net carbs, while America shows total carbs. Calculate net carbs by subtracting fiber from total carbs.

Carbohydrate comes in two forms: net carbs and fiber. Net carbs are converted to glucose and raise your blood sugar, which we don't want on a ketogenic diet. some should stay below 25g. The other part of carbs is fiber: insoluble fiber just passes through your body without raising blood sugar, soluble fiber is used by gut bacteria to produce fatty acids which provides a few calories but does not raise blood sugar either.

  • g daily net carbs (changeable)

How Much Protein Should I Eat?

It is important to get enough protein to maintain your muscles, but not too much or it will kick you out of ketosis.

Based on your personal data, you should stay within a range of g if you are mostly sedentary to g if you put your muscles under a lot of new stress or with a large caloric deficit to prevent muscle loss.

When in doubt, choose the middle ground. For you, that's g.

When losing weight or under physical stress somewhat more protein than the RDA is probably justified. However, consuming too much protein can be problematic because extra amino acids can be converted to glucose in the body, driving down ketones and suppressing fat burning.

See Protein Intake While Dieting and the book The Art and Science of Low Carbohydrate Performance for details. The maximum protein level used here is based on research paper "Dietary protein for athletes: From requirements to optimum adaptation" analyzed in "The Myth of 1 g/lb: Optimal Protein Intake for Bodybuilders". Even professional body builders should have no benefit in going above the upper limit used here. The values here are in g/lbs of lean bodymass, while in the previous link they talk about g/lbs of total body weight. That's why the number here seems a bit higher.

  • no exercisechosen amountvery active
    g minimum g chosen g maximum
    g/kg g/kg g/kg
    g/lbs g/lbs g/lbs

How Much Fat Should I Eat?

Eat fat to your liking. Now that you have chosen g of carbs and g protein, you have already kcal of your daily requirements covered with these nutrients. What's left for you to choose is how much fat to eat.

Here you can choose your caloric intake. Try a moderate deficit and only go lower if you feel comfortable after about a week.

Fat intake depends on your goal. If you want to lose weight, your total calories have to be below your maintenance calories of kcal. Think of fat as your healthy filler nutrient: To maintain your current weight, fill all of the remaining calories up with g fat. Don't go below g of fat.

If you want to lose weight, your total calories have to eat less than kcal. How low can you go? This depends on the maximum rate your body can release body fat (See discussion 1 and 2). If you eat below g of fat, your body cannot keep up any more with burning your body fat for fuel and will start burning protein – meaning you will lose your hard earned muscles instead of more fat. You don't want that.

Also, you should not go below 30g of daily fat to prevent formation of gallstones. (See TAaSoLCL page 168).

  • lowest intakechosen intakemaintenance
    % deficit % deficit % deficit
    kcal min kcal chosen kcal max
    g fat min g fat chosen g fat max

Your Personal Results

Here are your personal macros:

kcal Daily Calorie Intake
g Carbs (%, kcal)
g Protein (%, kcal)
g Fat (%, kcal)

If these numbers are too confusing, here is a visual representation of your macros and your deficit. The size of each area is correctly scaled based on your ratios.

Weight Maintainence
Your Target

If you stick to g of carbs, g protein, and g fat, you will eat kcal and lose kg (lbs) in the first month. Keep in mind that your body weight can fluctuate by ±2kg (±4lbs) on any given day from water weight and what's in your stomach. Recalculate your macro ratio once a month, because changes in body composition have a large influence on the recommendations and weight loss.

If you use MFP, update your custom goals with the percentages above. Note: percentage in MFP and above is calculated for calories.

Your Weight Loss Forecast

Now to fun stuff: a weight and body fat forecast for one year, starting today. Remember that this is just a rough estimate and your personal results can differ.

Choose kg or lbs, and then play around with your chosen fat intake to see how it affects weight loss.

  • Start on .
  • Show in kg or lbs

Please enter a date and click kg or lbs to show the graph.

For all you data junkies, you can download a CSV file of your projected weight loss. This contains all the data used in the above graph.

Got Questions?

Post Your Question to /r/keto

We can help you. , and replace the first text line with your question. Or click inside this field:

Copy its text with Ctrl+C. Go to /r/keto submit site, move to the "text" field, paste it with Ctrl+V, and replace the first line with your question.


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Created by Martin Ankerl. I am a software developer with interest in nutrition, specifically in the ketogenic diet. You can find me on reddit, Google+, Facebook, and my blog. If you want to support this site, you can donate here. Please read the disclaimer and Cookie Consent.