Olutil stands for Online Utilities — a growing suite of privacy-first, browser-native web tools. This sub-site offers health and fitness reference calculators that run entirely in your browser: body mass index, basal metabolism, daily energy expenditure, body fat, macros, calories, hydration, sleep cycles, one-rep max, running pace, heart rate zones, pregnancy and due dates, baby growth and ideal weight — in one place. All results are general estimates only, not medical, diagnostic or treatment advice. 100% Local Processing
Estimate body mass index and its WHO weight category from height and weight.
Estimate resting basal metabolic rate with the Mifflin-St Jeor equation.
Estimate total daily energy expenditure from BMR and activity level.
Estimate body fat percentage from tape measurements by the US Navy method.
Split a calorie target into daily protein, fat and carbohydrate grams.
Turn TDEE and a weight goal into a suggested daily calorie target.
Estimate a daily water intake reference from weight, activity and weather.
Find suggested bed or wake times around 90-minute sleep cycles.
Estimate your one rep max from a weight and a rep count.
Get pace, speed and splits from a distance and time.
See five training heart rate zones from age and resting heart rate.
Estimate current pregnancy weeks, days and trimester from your LMP.
Estimate an expected delivery date from your last period.
Estimate approximate WHO weight and height percentiles by age and sex.
See a reference ideal weight range from four common formulas.
All tools on this site do their work locally in your browser. The heights, weights, dates and numbers you type are never sent to any server, so your data stays on your device. Pick a tool, fill in the fields, press the calculate button and read, copy or print the result.
Yes. Every tool on this site is free to use, with no account and no sign-up required.
No. All results are general estimates, not medical, diagnostic or treatment advice. For pregnancy, due dates and baby growth, follow your doctor and official references such as WHO. For fitness and nutrition, consult a qualified professional.
Yes. All processing runs locally in your browser. The figures you enter are not uploaded to any server, and the tools work offline once the page has loaded.
Yes. Most tools support one-click printing via your browser print dialog, and some let you copy the text to paste into your records.