About Cira

Cira is a caffeine tracker for iPhone. It shows how much caffeine is still active in your body and the latest hour you can have a drink and still sleep.

What this site is

The site is the reference behind the app. It holds the same figures the app calculates with: how much caffeine is in 36 drinks, how long a dose lasts, and how late you can drink it for a given bedtime. Everything here is free to read and works without the app.

How the numbers are worked out, and which of them rest on published research, is set out on the methodology page.

What the app adds

The pages here answer one drink at a time. The app keeps the whole day in view: it adds up every drink you log, draws your own curve, and reminds you before the last cup that would cost you sleep. It runs on iPhone, with a Home Screen widget and a Lock Screen view.

Cira on the App Store is free to download.

Privacy

The app works without an account. What you log stays on your iPhone. This site has no sign-up and no advertising. The details are in the privacy policy.

Who makes it

Cira is made by an independent developer. It is not funded by, or affiliated with, any coffee, tea or energy drink brand, and no brand pays to appear on this site.

Corrections

If a figure here looks wrong, or a drink is missing, write to bonis22311@gmail.com. Corrections are made in the app and on the site together, so the two never disagree.

Not medical advice

Cira is a tracker, not a medical device. The figures describe a typical healthy adult, not you. If caffeine affects your heart, your anxiety or a pregnancy, talk to a doctor.