16 tools · free · no sign-up
Every number that matters for building muscle
Body composition, nutrition and training — each calculator shows its formula, its limits and what to do with the answer. Your inputs are remembered on this device, so you only type your height once.
Know your body
Body composition
What you are made of, and how much room there is to grow.
Muscle PotentialFlagshipHow much muscle you can realistically build — and how long it takes.Open FFMI CalculatorFat-free mass index, normalised for height, with context bands.Open Body Fat CalculatorU.S. Navy tape-measure method, with a BMI comparison.Open Lean Body Mass CalculatorLean mass from body fat — or from the Boer, James and Hume equations.Open Waist-to-Height RatioThe simplest useful screen for central fat: keep your waist under half your height.Open Target Body FatWhat you will weigh at a target body fat — and how much fat that means losing.Open
Know your numbers
Nutrition
Calories and macros that match the goal, not a generic diet.
TDEE & BMR CalculatorMaintenance calories with three BMR equations compared.Open Protein CalculatorDaily protein and per-meal targets from the best current evidence.Open Macro CalculatorProtein first, fat to a healthy floor, carbs fill the rest.Open Bulking CalculatorSurplus, rate of gain and calories for a lean bulk at your level.Open Cutting CalculatorDeficit, weekly rate and time to your target body fat.Open
Train better
Training
Loads, volume and progression you can take straight to the gym.
One Rep Max CalculatorEstimated 1RM plus a full percentage and rep table.Open RPE CalculatorLoad for any reps @ RPE, and e1RM from any set.Open Plate CalculatorExactly which plates to put on each side of the bar.Open Training Volume CalculatorWeekly hard sets per muscle, checked against the evidence.Open Progressive Overload PlannerDouble progression, week by week, plus what to do next session.Open