10.0

This free keto calculator finds your personal macros — the exact grams of fat, protein, and net carbs to eat each day to lose weight on the ketogenic diet. Enter a few details below and get your numbers in under a minute.

Built and maintained by Martin Leitner-Ankerl, a software developer who has followed and researched the ketogenic diet for years. The math uses the peer-reviewed Mifflin-St. Jeor equation. This is general information, not medical advice.

What is a ketogenic diet? (+ video tutorial)

A ketogenic diet is high in fat, moderate in protein, and very low in carbohydrates. When you cut carbs this far, your body switches from running on sugar to running on fat — producing ketones as fuel along the way. Most people start keto to lose weight, and many also find it steadies their energy, appetite, and blood sugar through the day. It isn't magic and results vary from person to person, but a lot of people find it easier to stick to than constant calorie counting.

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

Your Fat Loss Calculation

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

Female Male
lbs weight ( kg)
' " tall ( cm)
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 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 we calculate your actual total daily energy expenditure (TDEE). This is the number 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

📚 Want the science behind it? Books I recommend:

The Art and Science of Low Carbohydrate Living — book cover The Case for Keto by Gary Taubes — book cover The Obesity Code by Jason Fung — book cover Good Calories, Bad Calories by Gary Taubes — book cover

Macronutrients are nutrients that provide energy for your body.

How Many Carbs Can I Eat?

Most people stay in ketosis somewhere between 20 and 50g of net carbs a day. This calculator starts you at 25g — a sweet spot that works for the majority. Spend those carbs wisely: get them from vegetables (10–15g), nuts and seeds (5–10g), and a little fruit (5–10g) rather than from sugar and grains. One catch with labels: in Europe they usually already show net carbs, while in the US they show total carbs, so subtract the fiber yourself.

Net carbs vs. fiber — what actually counts?

Total carbohydrate is made up of net carbs plus fiber. Net carbs are the part that turns into glucose and raises your blood sugar — exactly what you want to limit on keto, which is why most people aim for 20–25g a day. Fiber is the rest, and it's good for you: insoluble fiber passes straight through without touching your blood sugar, while gut bacteria ferment soluble fiber into fatty acids that add only a few calories and don't spike glucose. That's why keto counts net carbs and lets fiber off the hook.

  • 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 above g if you are mostly sedentary. You can go as high as g if you put your muscles under a lot of new stress or with a large caloric deficit. High protein prevents muscle loss.

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

Why not just eat more protein?

When you're losing weight or under physical stress, eating somewhat more protein than the RDA is a good thing — it protects your muscle. Going far above what you need can work against ketosis, though: the body can convert the excess amino acids into glucose, which nudges ketone levels down. So don't fear protein — just don't massively overshoot the maximum below.

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 the 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 body mass, 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 exercise chosen amount very 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. You have chosen g of carbs and g protein. This means you have already kcal of your daily requirements covered. 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.

How low can your calories go?

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 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 above g of fat, your body burns only fat and you will lose weight. If you eat below that, your body will start burning protein. This means your body cannot produce that many calories from fat only. You will start to lose your hard earned muscles. You don't want that.

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

  • lowest intake chosen intake maintenance
    % 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 / day
daily calorie target
g Carbs % · kcal
g Protein % · kcal
g Fat % · kcal

Rough daily comparisons spread across all your meals — mix and match real foods, these aren't exact.

These numbers are estimates, not medical advice. They come from the Mifflin-St. Jeor equation and your lean body mass — a solid starting point, but everyone is different. Adjust based on how you feel and your real results, and talk to your doctor before big dietary changes, especially if you have a health condition. See the full disclaimer.

Copies a link that reopens this calculator with your numbers already filled in — handy for saving or sharing on Reddit.

Here is a visual representation of your macros and your deficit. The area of the circles is exactly scaled based on your ratios.

Weight Maintenance kcal
Your Target kcal
Deficit kcal

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! 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 the fun stuff: a weight and body fat forecast for one year, starting today. Remember that this is 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.

Keto Calculator FAQ

How many carbs can I eat on keto?

Most people stay in ketosis on 20–50 grams of net carbs per day. This calculator defaults to 25 grams, which works well for the majority. Get your carbs from vegetables, nuts, and a little fruit rather than from sugar and grains.

How much protein should I eat on keto?

Protein is set from your lean body mass, not your total weight — roughly 1.3 to 2.2 grams per kilogram of lean mass. The calculator gives you a personalized minimum and maximum so you keep muscle without eating so much that it interferes with ketosis.

What is a macro?

"Macro" is short for macronutrient — the three nutrients that give your body energy: fat, protein, and carbohydrates. On keto you eat high fat, moderate protein, and very few carbs.

What is the difference between net carbs and total carbs?

Net carbs are total carbohydrates minus fiber (and sugar alcohols). Fiber does not raise blood sugar, so keto counts net carbs. European labels already show net carbs; United States labels show total carbs, so subtract the fiber yourself.

What foods are high in fat for keto?

Good keto fat sources include avocado, olive oil, coconut oil, butter, nuts and seeds, fatty fish like salmon, eggs, and full-fat cheese. These let you reach your fat target while keeping carbs low.

How fast will I lose weight on keto?

It depends on the calorie deficit you choose. A deficit that loses 0.5 to 1 kilogram per week is sustainable for most people. Expect a larger drop in the first week as your body sheds water weight, then a steadier loss after that.

How does this keto calculator work?

It estimates your Base Metabolic Rate with the Mifflin-St. Jeor formula, multiplies it by your activity level to get your daily energy needs, then subtracts your chosen deficit. Protein comes from your lean body mass and carbs from your chosen limit; the remaining calories become your fat target.

Is this medical advice?

No. This calculator provides general information to help you plan a ketogenic diet and is not a substitute for professional medical advice. Talk to your doctor before making big dietary changes, especially if you have a health condition.

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.

Comments

Is this calculator useful to you? Share your thoughts!

Created by Martin Leitner-Ankerl. I am a software developer with interest in nutrition, specifically in the ketogenic diet. You can find me on reddit and my blog. Please read the disclaimer and Cookie Consent.