Macronutrients (Macros)

Macronutrients, often shortened to “macros,” are fat, protein and carbohydrate. Nutrition plans express them in grams, as a share of total energy or both. Ketogenic patterns use a very-low-carbohydrate, higher-fat distribution, but a stated ratio alone does not guarantee a particular blood-ketone value.

What are the three macros?

General nutrition calculations use about 9 kcal per gram of fat and 4 kcal per gram of protein or carbohydrate.¹ These factors are useful conversions, not statements that every carbohydrate component has identical digestion or energy availability. Fibre, polyols and allulose require the definitions used by the applicable label system.

Macro	Calories per gram	Main role on keto
Fat	9	Often supplies the largest energy share
Protein	4	Supplies amino acids and supports tissue maintenance
Carbohydrate	4	Restricted according to the stated dietary protocol

What is the standard keto macro split?

A commonly cited ketogenic distribution is about 70–80% of energy from fat, 10–20% from protein and 5–10% from carbohydrate.¹ At 2,000 kcal, those percentages convert to about 156–178 g fat, 50–100 g protein and 25–50 g carbohydrate. They describe one formulation range, not a physiological switch or a personal prescription. Protein should be individualized for body size, age, activity, energy intake and clinical goals. Human tracer studies do not establish a universal protein ceiling for ketosis; some glucogenic amino acids can contribute carbon to regulated gluconeogenesis.

How do you calculate your own macro targets?

Start with an estimated TDEE, then define the carbohydrate measure, protein target and remaining energy from fat. A range of 20–50 g nonfiber carbohydrate per day is often used to describe a very-low-carbohydrate ketogenic pattern, but it is not a guaranteed threshold for an individual.² Protein needs depend on body size, activity, health and the protocol being followed. The macro guide explains those assumptions. Once you have total-carbohydrate, protein and fat grams, the macro arithmetic worksheet converts them to 4/4/9 calories and percentages without replacing clinical instructions.

Common confusion points

• The carbohydrate measure must be stated. Research may report total or nonfiber carbohydrate; commercial “net carbs” is not standardized. On a US label, optional adjustments start from Total Carbohydrate. On an EU or UK label, Carbohydrate already excludes fibre, so fibre must not be subtracted again. The net-carb explainer shows both systems.
• "High protein" is relative to calories, not grams eaten. Protein grams on keto often resemble a non-keto diet; it's the percentage of calories that looks moderate because fat fills so much of the pie.
• Gluconeogenesis is regulated. Some glucogenic amino-acid carbon can contribute to glucose production, but human tracer studies do not establish one protein ceiling for ketosis.
• Ratios are starting descriptions, not rules. Targets shift with the dietary protocol, activity, goals and clinical context.

Frequently Asked Questions

What are the three macronutrients?

Fat, protein and carbohydrate. General nutrition calculations use about 9 kcal per gram of fat and 4 kcal per gram of protein or carbohydrate, although individual carbohydrate components can have different regulatory energy factors.

What is a common macro split for keto?

One commonly cited range is 70 to 80% of energy from fat, 10 to 20% from protein and 5 to 10% from carbohydrate. It is a formulation example, not an individualized prescription or guaranteed ketosis threshold.

Do macro targets need a carbohydrate definition?

Yes. State whether the target uses total, nonfiber or a specified label-based estimate. US and EU or UK labels use different carbohydrate and fibre definitions.

Why is protein often described as moderate?

Many ketogenic formulations allocate most energy to fat after setting carbohydrate and protein. Protein needs still depend on the person and protocol; tracer research does not establish a universal protein ceiling for ketosis.

See also: Net carbs · Total carbs · TDEE · Gluconeogenesis · Keto Glossary index · Macro arithmetic worksheet

Works cited

1. Diet Review: Ketogenic Diet for Weight Loss — Harvard T.H. Chan School of Public Health, Nutrition Source — August 23, 2026 https://nutritionsource.hsph.harvard.edu/healthy-weight/diet-reviews/ketogenic-diet/
2. Nutrition Therapy for Adults With Diabetes or Prediabetes: A Consensus Report — Alison B. Evert and colleagues, Diabetes Care, 2019 https://pmc.ncbi.nlm.nih.gov/articles/PMC7011201/

Article history

1. August 23, 2026Corrected protein and gluconeogenesis evidence limits; aligned carbohydrate targets with research definitions and US versus EU/UK label rules
2. August 19, 2026First published