Estimate BMR and TDEE
Your basal metabolic rate uses the Mifflin–St Jeor equation. Your selected activity factor then estimates total daily energy expenditure—the calories needed to maintain your current weight.
Fuel your training
Free Macro Planner
Fuel your inner Samson.
Estimate and customize daily calories, protein, carbohydrates, and fat for muscle gain, body recomposition, maintenance, or fat loss.
Understand your numbers
How this macro calculator works
Enter your bodyweight, height, age, gender, activity level, and goal. The calculator estimates the calories and macronutrients you can use as a practical starting point.
Set calories for your goal
Maintenance and recomp begin near TDEE. Muscle gain targets about 0.375% of bodyweight per week; fat loss targets about 0.75%. The calculator converts that weekly change into a daily calorie adjustment using approximately 7,700 calories per kilogram.
Build your macros
Protein is based on bodyweight and goal. Fat starts at 0.75 g/kg (about 0.34 g/lb), the midpoint of general guidance for active adults. Carbohydrates receive the remaining calories.
Protein by goal
Protein targets that support your training
Samsonizer adjusts protein upward when maintaining muscle becomes more challenging during a calorie deficit.
- Muscle gain
- 0.85 g per lb
- Maintenance / recomp
- 1.0 g per lb
- Fat loss
- 1.1 g per lb
The role of each macro
Why each macronutrient matters
Protein, carbohydrates, and fat each serve a distinct purpose. A practical plan gives every macro a role instead of eliminating one completely.
Protein
Supports muscle growth and repair while helping preserve lean mass—especially during weight loss.
Carbohydrates
Provide a primary source of energy for training, physical performance, and everyday activity.
Dietary fat
Supports hormone production, cell function, essential fatty-acid intake, and absorption of vitamins A, D, E, and K.
Methodology reviewed by David ValenzuelaNASM Certified Personal Trainer · NASM Certified Nutrition Coach
Questions, answered
Macro calculator FAQ
What is a macro calculator?
A macro calculator estimates how many calories and grams of protein, carbohydrates, and fat to eat each day based on your body, activity, and goal.
Should I use BMR or TDEE for my calorie target?
Use TDEE. BMR estimates the energy your body needs at rest, while TDEE includes daily activity and is the more useful starting point for maintenance, muscle gain, or fat loss.
How much protein should I eat each day?
This planner uses 0.85 g per pound for muscle gain, 1.0 g per pound for maintenance or recomp, and 1.1 g per pound during fat loss.
What is the AMDR for macros?
The Acceptable Macronutrient Distribution Range for adults is 10–35% of calories from protein, 45–65% from carbohydrates, and 20–35% from fat. These are general population ranges; athletic needs may differ.
How accurate are macro calculators?
They provide estimates. Track bodyweight trends, measurements, energy, hunger, and training performance for two to three consistent weeks before adjusting your target.
When should I recalculate my macros?
Recalculate after a meaningful change in bodyweight, training volume, daily activity, or goal. Small day-to-day fluctuations usually do not require a new plan.
Who's Samson?
Samson is the biblical figure known for extraordinary strength. His story inspired our chain-breaking logo and the name Samsonizer: a call to fuel your training, strengthen your habits, and break through the barriers holding you back.