Why these tools exist
Health information is everywhere but actionable numbers are rare. You know sleep matters — but which bedtime actually lines up with a complete sleep cycle? You know BMI has limits — but what does your number mean in the context of WHO categories? These tools skip the articles and go straight to the answer. They don't replace medical advice, but they give you the same arithmetic your doctor uses so you can show up to the conversation informed.
Which calculator for which question
- BMI Calculator — Body Mass Index with WHO categories and metric/imperial input.
- Sleep Calculator — Optimal bedtimes based on 90-minute sleep cycles.
- Due Date Calculator — Estimated due date with trimester milestones and weekly progress.
- Running Pace Calculator — Calculate pace, finish time, or distance from any two inputs.
Using these tools wisely
- BMI is a population metric, not a personal diagnosis. It doesn't account for muscle mass, bone density, or fat distribution. Use it as a starting point, not a verdict.
- Sleep cycles vary by person. The 90-minute average is well-supported, but individual cycles range from 70 to 110 minutes. If the calculator's suggestion leaves you groggy, shift by 10 minutes and experiment.
- Due dates are estimates, not appointments. Only about 5% of babies are born on their calculated due date. The 40-week calculation is a statistical average — 38–42 weeks is considered normal.
- Running pace compounds over distance. A 10-second-per-km difference is insignificant over 1 km but means 2+ minutes over a half-marathon. Use the pace calculator before a race to set realistic split targets.
Frequently asked questions
How do I calculate my BMI?
BMI (Body Mass Index) is your weight in kilograms divided by your height in metres squared. A BMI between 18.5 and 24.9 is considered healthy, though BMI is a screening tool and not a diagnostic measure.
How much sleep do I need per night?
Most adults need 7–9 hours of sleep. The sleep calculator helps you find optimal bedtimes based on 90-minute sleep cycles, so you wake up between cycles feeling refreshed.
How is a pregnancy due date calculated?
The standard method adds 280 days (40 weeks) to the first day of the last menstrual period. Our due date calculator also shows trimester milestones and week-by-week progress.