Health & Fitness Calculators

Maintenance calories — your BMR scaled by activity, the number to plan around.

Estimate body fat from a tape measure — the US Navy circumference method, with neutral reference bands.

A reference weight range from four classic formulas — a spread, never a single target.

A daily water target from your weight, activity, and climate — in liters, cups, and ounces.

Daily protein in grams from your weight and goal — with the goal’s evidence range.

Estimate your 1RM from reps — Epley and Brzycki, plus a %-of-1RM table for programming.

Running pace per km and per mile from distance and time — plus speed in km/h and mph.

Body mass index with the WHO band and the healthy weight range for your height, not a single target.

Waist divided by height, the measure NICE puts alongside BMI because BMI cannot see where mass sits.

Protein, fat and carbs from your calorie target, set in the order that keeps protein from collapsing.

How long a given daily deficit takes to reach a target weight, with the straight-line assumption stated.

Five training zones from Tanaka max heart rate, using heart-rate reserve when you know your resting pulse.

Naegele due date adjusted for your cycle length, with gestational age and the ACOG term windows.

The six-day fertile window that ends on ovulation day, projected across your next few cycles.

Energy cost of an activity from its MET value, your weight and the time spent.

Bedtimes and wake times spaced by sleep cycles, with how variable a cycle really is.

Lean mass and fat mass from height and weight, across the published formulas.

Steps into distance using a stride length from your own height, not an average.