Plan a bedtime from your wake-up time, chosen sleep duration and estimated time to fall asleep. The calculator is an adult scheduling aid. It does not claim to find a perfect bedtime by dividing sleep into identical 90-minute cycles.
Convert a chosen daily fluid plan from cups to millilitres and litres. This calculator helps you understand how cup size changes the volume in a plan. It does not prescribe a personalised water requirement from weight, sex or age.
Estimate the energy used during an activity from body weight, duration and an activity-specific MET value. The tool displays both gross energy, which includes resting energy during that period, and an above-rest estimate. Choose an appropriate MET value rather than assuming all walking or running has one intensity.
Estimate body-fat percentage indirectly from BMI, age and the sex category used in the Deurenberg adult equation. This is a population-based prediction, not a measured body-fat result. It is useful for understanding the calculation’s assumptions and its potential error.
Estimate resting energy expenditure using the Mifflin–St Jeor equation for adults. Often called a BMR calculator online, this formula estimates energy use at rest rather than measuring strict basal metabolism. The result is not your total daily calorie need or a recommended diet intake.
Calculate adult body mass index (BMI) from weight in kilograms and height in centimetres. The result is a screening measure that relates weight to height. This page uses adult categories for people aged 20 or older; it is not a child growth-chart calculator.
Explore a longevity planning scenario by entering your current age and an assumed number of remaining years. This page does not predict your personal lifespan. The tool deliberately uses your stated assumption rather than manufacturing a health-based death-age score.
Calculate the date you reach a chosen retirement age and the calendar time remaining from a reference date. You supply the age appropriate to your own plan or scheme. This page does not assume that one national retirement age applies to every worker.
Twins can have different recorded birth times even when they share a birthday. Compare two birth records to calculate the time gap in days, hours and minutes. This guide explains what that gap means for calendar age and what it does not imply about development or identity.
Compare a dog’s age with an illustrative human-age equivalent. Dogs do not age at a constant seven human years per dog year, and size and breed affect ageing. This simple model is useful for explaining that difference, not for deciding a pet’s care requirements.
