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Keto Diet Macro Calculator

Calculate your daily fat, protein, and carb targets for a ketogenic diet based on your calorie needs.

Result

Fat
161g (0.7%)
Protein
112g (0.2%)
Net Carbs
25g (0.1%)

Uses a moderate protein target of 0.7g per pound of body weight, with net carbs held to your specified daily limit and fat filling the remaining calories - the hallmark of a ketogenic diet's macro split (typically 70-75% fat, 20-25% protein, 5-10% carbs).

About the Keto Macro Calculator

The Keto Diet Macro Calculator converts a daily calorie target into the three macronutrient amounts a ketogenic eating plan is built around: fat, protein, and net carbohydrates. It is intended for someone who already has a calorie goal in mind and wants to see how those calories should split into gram targets that fit a low-carb, high-fat pattern. Because keto is defined largely by how tightly carbohydrate intake is restricted, the tool treats net carbs as a fixed daily ceiling and fills the remaining calorie budget with fat once protein is accounted for.

How It Works

You enter your daily calorie target, current body weight in pounds, and a net carb ceiling (20 to 30 grams is the range typically used for standard keto). Protein is calculated first, at 0.7 grams per pound of body weight, then converted to calories at 4 calories per gram. Carb calories are found the same way from your net carb target, also at 4 calories per gram. Whatever calories remain after subtracting protein and carb calories from your total becomes the fat target, converted to grams at 9 calories per gram, and each macro is shown as both grams and a percentage of total calories.

Protein (g) = body weight (lb) x 0.7. Protein calories = protein (g) x 4. Carb calories = net carb target (g) x 4. Fat calories = daily calories - protein calories - carb calories, floored at 0. Fat (g) = fat calories / 9.

Formula & Methodology

To work this out by hand, multiply body weight in pounds by 0.7 to get grams of protein, then multiply that by 4 for protein calories. Multiply the net carb gram target by 4 for carb calories. Add the two together and subtract from the total daily calorie target; whatever is left is the fat calorie allowance, which divides by 9 (since fat carries more calories per gram than protein or carbs) to produce the fat gram target.

Examples

2,000 calorie target, 160 lb body weight

With a 25 g net carb target, protein is set at 112 g (about 22% of calories), net carbs stay at 25 g (about 5%), and fat fills the remainder at roughly 161 g (about 73%).

1,800 calorie target, 130 lb body weight

With a 20 g net carb target, protein comes out to 91 g (about 20%), net carbs remain at 20 g (about 4%), and fat fills the rest at roughly 151 g (about 75%).

Advantages

  • Converts a single calorie number into three concrete gram targets, removing the manual arithmetic of splitting protein, fat, and carbs by hand.
  • Uses body weight directly for the protein target, so the figure scales for larger or smaller individuals rather than applying a flat percentage.
  • Shows both grams and percentage of calories for each macro, making it easy to see whether the split matches typical ketogenic ratios.

Common Mistakes

  • Entering total carbs instead of net carbs, which understates how much room is actually available once fiber is subtracted.
  • Setting a calorie target too low relative to body weight, which drives protein and carb calories to consume the entire budget and leaves zero grams of fat.
  • Treating the 0.7 g/lb protein figure as fixed for every situation, when higher training volume would call for adjusting body weight or the multiplier upward manually.

Edge Cases to Watch For

  • If protein and carb calories together exceed the daily calorie target, fat calories are floored at 0 rather than going negative, so the displayed fat grams and fat percentage both show 0, a signal that the calorie target is too low for the chosen body weight and protein multiplier.
  • The 0.7 g/lb protein multiplier is fixed and does not adjust for activity level, so a very active user and a sedentary user of the same body weight get identical protein grams.
  • Net carbs are taken as a direct input rather than derived from total carbs minus fiber, so the figure entered should already represent the net (digestible) carb count intended for the day.

Common Use Cases

  • Someone starting a ketogenic diet who has a calorie target from another calculator and needs it translated into daily fat, protein, and net carb grams.
  • Someone tracking macros in a food log who needs numeric targets to enter for each macronutrient.
  • Someone adjusting their net carb ceiling to see how tightening or loosening it changes the fat and protein split at the same calorie level.
Written & fact-checked by the Calculateus TeamLast updated August 5, 2026How we verify our formulas

Frequently asked questions

Why does keto cap carbs so low specifically?

The ketogenic diet works by depleting the body's glycogen (stored carbohydrate) reserves enough to shift metabolism toward burning fat and producing ketones for fuel, a state called ketosis - staying under roughly 20-30g of net carbs per day is generally needed to maintain this metabolic state, since higher carb intake replenishes glycogen and interrupts ketosis for most people.

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Conclusion

The calculator provides a straightforward starting point for structuring a ketogenic macro split from a calorie target and body weight. Because the net carb ceiling and protein multiplier are both adjustable, it can be re-run to see how different targets shift the resulting fat and protein grams.

References