Keto Macro Calculator

How We Calculate Your Macros

Calculating your macros isn't magic-it's biology. We use a multi-step process to ensure your targets are both scientifically grounded and practically achievable for a low-carb lifestyle.

1. Finding your BMR

First, we calculate your Basal Metabolic Rate (BMR) using the Mifflin-St Jeor equation. This is the number of calories your body burns just staying alive (breathing, circulating blood, cellular repair) if you were to stay in bed all day. It is widely considered the most accurate formula for healthy adults.

2. Factoring in Activity (TDEE)

We then apply an activity multiplier to your BMR to find your Total Daily Energy Expenditure (TDEE). This represents the total number of calories you actually burn in a day.

3. Adjusting for Your Goal

• Lose Weight: We subtract 500 calories from your TDEE. This creates a deficit that typically leads to about 0.5kg (1lb) of fat loss per week-a rate that is sustainable and helps preserve muscle mass.
• Maintain: We keep your calories at your TDEE level.
• Build Muscle: We add 250 calories to your TDEE to provide the extra energy needed for muscle synthesis while minimising fat gain.

4. Setting the Macro Split

Unlike "standard" calculators that use fixed percentages, we prioritise macros based on your body's needs:

• Protein (1.8g per kg): We set protein high enough to protect your muscles, especially during weight loss. Protein is also the most satiating macronutrient, helping you feel full.
• Net Carbs (25g/50g): We apply a strict cap. For keto, 25g is the "gold standard" to ensure you remain in ketosis. For low carb, 50g allows for more flexibility with vegetables and fruit.
• Fat: The remaining calories come from healthy fats. On a low-carb diet, fat is your primary fuel source.