Sleep
How Much Sleep Adults Actually Need, and Why Consistency Matters
Seven to nine hours covers most adults, but a steady wake time may do more for how you feel than the total on any single night.
Health Tools, Calculators and Trackers
Eleven tools that do one useful thing each and then get out of the way. They run entirely in your browser — nothing is uploaded, nothing is sold, and anything you save stays on this device.
All tools
Pick the tool that matches the question you actually have
Grouped by what you are trying to do, not by what kind of maths sits behind them.
Understand what you are feeling
Start here when something is off and you are not sure what it means or how urgent it is.
Know your numbers
The measurements that show up in every check-up, explained rather than just calculated.
Instant
BMI Calculator
Body mass index in metric or imperial units, with the healthy-weight range for your height — and an honest account of what BMI cannot tell you.
Open tool Saves locallyWellness Score
A ten-question self-check across sleep, movement, food, mind and prevention — and the one area where a small change would go furthest.
Open toolTrack what changes
One reading tells you very little. A month of readings tells you a great deal.
Saves locally
Blood Pressure Tracker
Log readings with date, time and pulse. See your average, your trend, and which category it falls in — then print the log for your appointment.
Open tool Saves locallyBlood Sugar Tracker
Record glucose readings in mg/dL or mmol/L with the context that makes them meaningful — fasting, before a meal, after a meal, or bedtime.
Open tool DailyHealth Journal
One daily entry for sleep, mood, energy, movement, food, symptoms and notes — with weekly and monthly dashboards that show the pattern.
Open toolPlan the day
Small planning tools for sleep, fluid and effort — the things you decide daily.
Instant
Sleep Planner
Work backwards from your alarm to find bedtimes that end on a sleep cycle, plus a wind-down schedule for the hours before.
Open tool InstantWater Intake Calculator
An estimate of daily fluid from drinks based on your body size, activity and climate — with the caveat that thirst is usually a better guide.
Open tool InstantHeart Rate Zones
Five training zones from your age and resting heart rate, using the Karvonen method when you have a resting number to give it.
Open toolGet ready for care
Walk into an appointment with everything the clinician needs, already written down.
Printable
Medication List Builder
One printable list of every prescription, over-the-counter medicine, vitamin and supplement you take — the single most useful thing to carry.
Open tool PrintableAppointment Prep
Turn a vague worry into a clear, printable one-page brief: why you are there, what changed, your questions, and your medication list.
Open toolPrivacy
How these tools handle your information
Everything runs in your browser
Every calculation happens on your own device in JavaScript. Nothing you type is sent to Health Captain, to an analytics service, or to anyone else. The trackers save to this browser’s localStorage, which means the data lives on this device, in this browser, and nowhere else — it does not sync to your phone, and it is not tied to an account, because there is no account. You can export any tracker to CSV and open it in a spreadsheet, and you can clear everything in one click with the reset button on each tool. Clearing your browser data, using private browsing, or switching devices will also make saved entries disappear, so export a copy if the record matters to you. Health Captain does not claim HIPAA compliance for data stored in your browser: these tools are educational, they are not a medical record, and no covered-entity relationship is created by using them. Read the full privacy policy.
No account, ever
There is nothing to sign up for and no password to lose. Open the tool and start.
Export whenever you want
Every tracker writes a plain CSV you can keep, print, or hand to a clinician.
Delete in one click
The reset button on each tracker wipes that tool’s data from this browser immediately.
Which tool should I use?
Start from the situation, not the tool
Six things people arrive here trying to do, and the tool built for each.
“My doctor asked me to check my blood pressure at home”
Log each reading with the date, time and pulse, then print or export the whole log for your next visit — home averages are what clinicians actually want to see.
Open the Blood Pressure Tracker“I have a new prescription”
Add it to one list alongside everything else you take, including vitamins and herbal products, so every clinician and pharmacist is working from the same page.
Open the Medication List Builder“I keep waking up tired”
Work backwards from your alarm to find bedtimes that end on a sleep cycle, then log how you actually sleep for two weeks to see the pattern.
Open the Sleep Planner“I have an appointment next week and always forget my questions”
Build a one-page brief — why you are going, what changed, your questions, your medicines — and print it the night before.
Open Appointment Prep“Something feels off and I do not know if it is urgent”
Choose a body area and a symptom to see categories of possible causes, the questions worth thinking through, and the warning signs that mean seek care now.
Open the Symptom Explorer“I want one place to see whether anything is changing”
One short daily entry covering sleep, mood, energy, movement, food and symptoms, with weekly and monthly views that show the trend.
Open the Health JournalNone of these tools is for an emergency
If you believe you are experiencing a medical emergency, call emergency services immediately (911 in the United States). Nothing here can assess you, and no tool should delay care you think you need. See our emergency resources.
From the blog
Reading that makes these numbers mean something
A calculator gives you a number. These explain what to do with it.
Heart Health
DASH or Mediterranean: Which Eating Pattern Should You Follow?
Both have strong cardiovascular evidence and they overlap heavily. Consistency with either matters far more than choosing between them.
Heart Health
Measuring Blood Pressure at Home Without Inflating the Number
Poor technique can add 10 to 20 mmHg. Six steps make home readings accurate enough to guide treatment decisions.