Free tools

Every number, computed properly.

35 free calculatorsfor training, nutrition and health — the real formulas, interactive charts, and an honest note on what each number can and can’t tell you.

35 calculatorsMetric + imperialNo signupNo stored data

Body & Composition

Where your body sits today — mass, fat, frame and the ranges that actually apply to you.

BMI CalculatorBody mass index, and where you sit on the healthy range.

Body Fat CalculatorBody fat percentage from tape measurements — no calipers.

Army Body Fat CalculatorThe U.S. Army tape-test standard, by age and sex.

Lean Body Mass CalculatorHow much of you is not fat — three formulas compared.

Ideal Weight CalculatorFour classic formulas and the healthy BMI band for your height.

Healthy Weight CalculatorThe weight range that counts as healthy for your height.

Body Type CalculatorYour shape and ratios from three tape measurements.

Body Surface Area CalculatorBSA by four clinical formulas — the dosing number.

BMR CalculatorWhat you burn at rest, by the three standard formulas.

Energy & Nutrition

What you burn and what to eat for it — calories, macros and the split between them.

Calorie CalculatorDaily targets for cutting, maintaining or gaining — with a projection.

TDEE CalculatorYour true daily burn, and what a cut or bulk does to it.

Calories Burned CalculatorWhat any workout actually burned, from MET values.

Macro CalculatorCalories → grams of protein, carbs and fat.

Carbohydrate CalculatorDaily carbs for your training volume, in grams.

Protein CalculatorHow much protein you actually need, per day and per meal.

Fat Intake CalculatorDaily fat grams, and where the saturated ceiling sits.

Performance

Pace, power and heart rate — the numbers that decide how hard you can go.

Pace CalculatorPace ↔ time ↔ distance, with full race splits.

One Rep Max CalculatorYour 1RM from any set, plus the %1RM programming table.

Target Heart Rate CalculatorThe Karvonen method — targets built on your resting HR.

Heart Rate Zone CalculatorAll five training zones, and what each one is for.

Max Heart Rate CalculatorFour max-HR formulas — and why 220 − age is the worst one.

VO₂max CalculatorThree ways to estimate your engine, ranked for your age.

Race Time PredictorAny race result → predicted times at every distance.

Recovery & Sleep

The other half of training — sleep timing, sleep debt and what your HRV means.

Sleep CalculatorBedtimes that land your alarm between sleep cycles.

Sleep Debt CalculatorYour week's shortfall, and a realistic payback plan.

HRV CalculatorWhere your HRV sits for your age — and why baselines beat norms.

Pregnancy & Cycle

Dates, windows and weight ranges through pregnancy and the menstrual cycle.

Pregnancy CalculatorHow far along, which trimester, and every milestone ahead.

Pregnancy Weight Gain CalculatorThe recommended gain curve for your BMI, week by week.

Pregnancy Conception CalculatorWork backwards to the likely conception window.

Due Date CalculatorYour due date — and the realistic window around it.

Ovulation CalculatorYour fertile window, mapped over the next few cycles.

Conception CalculatorThe days that actually matter for conceiving.

Period CalculatorYour next periods, mapped months ahead.

Health

Clinical estimates worth knowing — kidney function and blood alcohol.

GFR CalculatorKidney function from a creatinine result — CKD-EPI 2021.

BAC CalculatorEstimated BAC now, and the honest hours back to zero.

Training Library

173 exercises, mapped muscle by muscle.

Every exercise in the Helix catalog — which muscles it hits and how hard, the equipment it needs, and how long each muscle takes to recover.

Browse the library →