TDEE & Macro Calculator
What you burn in a day, and the calories and macros to hit your goal. Start here if you are not sure where to start.
Start here
Body Fat Percentage Calculator
The U.S. Navy tape method. A cloth tape and two minutes gets you closer to the truth than any scale.
Most useful
Protein Calculator
Your daily protein target and how to split it across meals, adjusted for goal, training and age.
Do this second
Macro Calculator
Protein, carbohydrate and fat in grams, built from your numbers and the split that suits how you eat.
Nutrition
BMR Calculator
What your body burns doing nothing. Mifflin-St Jeor, Katch-McArdle and Harris-Benedict side by side.
Foundation
Calories Burned Calculator
What a session actually costs, by activity and bodyweight. Based on published MET values, not a watch.
Training
One Rep Max Calculator
Estimate your max from any set, then the exact weight for every training percentage.
Strength
Lean Body Mass Calculator
Everything you are made of except fat. The number that sets your protein and your resting burn.
Body comp
FFMI Calculator
How much muscle you carry for your height, and where that sits against what training alone produces.
Body comp
Water Intake Calculator
How much water you need, adjusted for bodyweight, training time, sweat rate and climate.
Recovery
- Body fat percentage — tells you how much of you is lean mass.
- Lean body mass — the engine, and what it should weigh at any leanness.
- Protein — set from lean mass, this is what protects it.
- TDEE and macros — the calories built around that protein.
- One rep max — the loads you train at to make the whole thing work.
Free fitness and nutrition calculators
Ten tools, no sign-up, no email gate. Every one gives you the number first and explains what to do with it second. They are built on the equations that strength coaches and researchers actually use — Mifflin-St Jeor, Katch-McArdle, the U.S. Navy circumference method, Epley and Brzycki — and they are written by a man who has spent thirty years applying them to his own body and to the people he coaches.
Why numbers beat guessing
Most people who are stuck are not lazy. They are working hard against a target they picked out of thin air. They are eating what feels like a lot of protein, training what feels like hard enough, in what feels like a deficit. Feelings are a terrible instrument. A number you can check every four weeks is how you find out whether the work is doing anything, and it is the difference between a year of progress and a year of effort.
How often to run them
Body fat and lean mass every four to six weeks — they move slowly and checking daily just makes you anxious. Calories and macros every time your weight changes by ten to fifteen pounds, because a smaller body burns less. One rep max whenever a training block ends. Water intake once, unless the season or your training volume changes.
Who is behind them
Jon Andersen is an IFBB professional bodybuilder, a former world-class strongman and powerlifter, and the author of the Deep Water Method. He is 54 and still training. These tools reflect how he actually works with clients: establish the real numbers, hold them long enough to mean something, then adjust from evidence rather than mood.
Ready to stop guessing entirely? Work with Jon one-on-one →
