Protein Calculator
How many grams of protein you need a day to build muscle, or keep the muscle you have while the fat comes off.
What is a macro calculator?
A macro calculator breaks your daily calorie target into the three macronutrients that matter most: protein, carbohydrates, and fat. Knowing your macros lets you build muscle, lose fat, or maintain weight while optimizing energy, recovery, and hormones.
This free tool uses the scientifically validated Mifflin–St Jeor equation to estimate your BMR, then factors in activity, goal, and diet preference to deliver personalized targets.
Frequently asked
Want these macro targets turned into a full meal by meal plan with recipes, shopping lists, and supplement timing?
Get your meal guide →Or start the free 7 day kickstart →What your numbers mean
Your protein number
Grams per day, set from your bodyweight. Split it across three or four meals rather than chasing it all at dinner; each feeding gives you another shot at the muscle building response.
Why it stays high in a deficit
When calories drop, protein is what decides whether the weight you lose is fat or muscle. It is the one number you hold constant while everything else moves.
What the rest of the calories do
Carbs fuel the training that gives protein something to build. Fat keeps hormones working. Neither is optional, which is why this tool never zeroes them out.
How to adjust after two weeks
- 1Weigh in the same way every morningAfter the bathroom, before food or water, same clothing. One day means nothing. The seven day average is the number you read.
- 2Compare week two's average to week one'sLosing fat: you want a half pound to one percent of bodyweight down per week. Building: a quarter to half pound up. Holding steady inside those ranges means the numbers are right, so leave them alone.
- 3Move calories, not everything at onceOff target for two straight weeks? Change calories by roughly 150 to 200 and hold protein exactly where it is. Protein is what protects the muscle you already built.
- 4Recheck the calculator when your weight moves 10 lbA lighter or heavier body burns a different amount. Ten pounds in either direction is the trigger to run these numbers again.
Numbers are the easy part.
Eating them every day is where people fall off. Turn these macros into a full 7 day meal and training plan, built around your body, free.
Start my free 7 day kickstartCommon questions
How much protein do I need a day?
Around 2.2 grams per kilogram of bodyweight, which is roughly 1 gram per pound, for anyone training hard. The calculator works it out from your actual bodyweight and raises it toward 2.6 g/kg when you select the high protein style or a muscle building goal.
How much protein to build muscle?
More than most people eat. Set your goal to build and the calculator pushes protein to the 2.2 to 2.6 g/kg range, then fills the rest of your calories with carbs for training fuel and fat for hormone health.
How much protein when losing weight?
Keep it high, higher than at maintenance. In a deficit your body will pull from muscle unless you give it a reason not to. Protein plus resistance training is that reason, which is why the calculator never drops protein when you cut calories.
Can you eat too much protein?
For healthy adults, intakes in this range are well tolerated in the research. The real cost is opportunity cost: calories spent on protein you did not need are calories not spent on training fuel. If you have kidney disease, ask your doctor before changing intake.
Do I need protein powder?
No. It is convenience, not magic. Chicken, beef, eggs, fish, dairy, and legumes all count the same. Powder just makes a 40 gram target easy on a day you are moving too fast to cook.