Health & Wellbeing2 min check

Keto Macro Calculator

Work out a starting point for daily fat, protein and carbohydrate targets on a ketogenic diet.

Short answer

Standard keto: ~70–75% of calories from fat, 20–25% protein, and 5% (typically ≤20–30 g) net carbs. We size your calorie target from weight, activity and goal, then split it into grams.

Step 1 of 10%

Calculation method, coverage and version

Inputs used: Body weight (kg), Height (cm), Age, Sex, Activity level, Goal, Daily net carbs (g).
Calculation approach: The calculator applies the rules and assumptions described in “How it works” to the values you enter. Rounding can cause small differences from an official or provider calculation.
Coverage: Health & Wellbeing. UK nations, tax treatment, local rules and provider criteria can differ; check the official sources shown below before acting.
Content version: No page-specific review date is currently published. Treat the result as indicative and verify current rules independently.

Not included unless explicitly requested: personal circumstances not entered, provider discretion, future rule changes, professional fees and case-specific exceptions. Read the full calculator methodology.

How it works

We estimate BMR with the Mifflin-St Jeor equation, multiply by activity to get TDEE, then adjust for your goal. Carbs are fixed at your chosen ceiling, protein at 1.6 g/kg to preserve muscle, and the rest of calories come from fat.

Worked example

80 kg, 175 cm, 35yo male, moderate activity, fat loss, 20 g carbs → ~2,200 kcal: 175 g fat, 128 g protein, 20 g net carbs.

Who should use this

•Adults trying a low-carb or ketogenic diet
•People wanting a starting macro split, not just calories

Common mistakes

×Counting total carbs instead of net carbs
×Setting protein too low (lose muscle) or too high (kicks you out of ketosis is mostly a myth, but crowds out fat)
×Not replacing electrolytes
×Eating too few calories — slows progress

Frequently asked questions

How long to get into ketosis?▾

Usually 2–7 days of staying under 20–30g net carbs. Test with urine strips or a blood ketone meter.

Is keto safe long-term?▾

Short-to-medium term evidence is reasonable for weight loss and blood-sugar control. Long-term safety is less clear — speak to your GP.

Do I need to count calories?▾

Many lose weight on keto without counting due to satiety, but if progress stalls, track for a week.

Can I drink alcohol?▾

Dry spirits and dry wine fit. Beer and sweet drinks don't. Tolerance drops sharply on keto.

Related calculators

Calorie Calculator →Protein Calculator →Weight Loss Calculator →BMI Calculator →