FitArbor

Health and fitness calculators built for privacy — nothing leaves your browser.

All tools run entirely in your browser — we don't store your data.

BMI Calculator

Get your BMI instantly with metric and imperial support, category on a visual scale, and healthy weight range.

Get your BMR, maintenance calories, and cut/bulk targets using Mifflin-St Jeor and other leading formulas.

Free macro calculator for any diet goal — keto, IIFYM, high-protein, vegan — with grams per day and per meal.

Calculate your due date from last period, conception date, or IVF transfer with trimester milestones.

Calculate your fertile window and ovulation day — see peak ovulation days for the next 3 cycles.

Calculate your daily hydration goal by weight, activity level, and climate in litres or oz.

Find the ideal bedtime or wake-up time based on 90-minute sleep cycles with a nap calculator.

Calculate body fat percentage using the U.S. Navy circumference method and BMI estimate by age and sex.

See ideal weight from four medical formulas side-by-side — honest ranges, not targets.

Solve pace, time, or distance — race finish predictor, per-mile/km split tables, and unit conversion.

Calculate your pet's age in human years using real veterinary science, not the outdated 7× myth.

Scale any recipe up or down by servings with density-aware cups-to-grams conversion for 30+ ingredients.