About RecompCalc

RecompCalc is a free collection of science-based fitness calculators. Enter a few numbers and get an instant answer (your calorie target, macros, protein, body fat or a realistic weight-loss timeline) with no account, no app and nothing to install.

What it is

A focused set of calculators built around two questions people actually search for: how to run a sensible calorie deficit, and whether body recomposition (losing fat and building muscle at once) is realistic for them. Around those sit the everyday tools that feed into them: TDEE, macros, protein and body fat percentage.

What it is not

It is not a meal-tracking app, not a food database, and not a place to create an account or buy a program. It is also not medical or nutritional advice: the figures are general estimates for education, not a personalised health plan. How each number is calculated, and the studies behind it, are laid out on the Our formulas page.

Why it exists

Most fitness calculators either hide their formulas or over-promise: the classic “lose a pound a week, forever” math that real life never follows. RecompCalc does the opposite: it uses well-established equations (Mifflin-St Jeor, Katch-McArdle, the US Navy method) and a metabolism-aware projection that stays honest about how weight loss actually slows over time.

Private by design

Every calculator runs entirely in your browser. The numbers you type are never sent to or stored on a server: they exist only on your device while you use the tool. You can read the details on our Privacy Policy.