What if you measured your life differently?
Enter your birthday once. See your life from four different angles — your age across the solar system, your weeks lived and remaining, where your years quietly went, and your next birthday on every planet.
Saved only in your browser. Never sent anywhere.
Enter your birthday above to see all four perspectives at once.
What is Parallax?
The word parallax comes from astronomy. It describes the small shift in an object's apparent position when viewed from two different vantage points. Astronomers use it to measure distance to nearby stars: the tiny shift in a star's position as Earth swings from one side of its orbit to the other reveals how far away the star really is.
This site applies the same idea to time. Your age, your weeks lived, your daily habits — these are all familiar quantities. But viewed from a different angle, they tell a story most people never see. You're 30 on Earth and 16 on Mars. You've used 1,820 of your 4,000 weeks. Of your last decade, roughly three years went to your phone alone. Same life, four parallax views.
The four calculators
Age on Other Planets — your age recalculated using each planet's orbital period as the unit of measure. The math comes from Kepler's third law: a planet's year is determined by its distance from the Sun. Mercury laps the Sun in 88 days. Neptune takes 165 Earth years. Same person, very different numbers.
Life in Weeks — the visualization Tim Urban popularized in his 2014 essay. A row per year, a square per week. When you see your whole life laid out as roughly 4,000 squares with several hundred already darkened in, time stops feeling infinite.
Time Dust — sleep, phone time, work, eating, commuting, waiting in lines. Each one feels small. Across 80 years they become the largest chapters. This calculator shows the actual years each one consumes. The phone number, in particular, surprises most people.
Cosmic Birthday — the exact Earth date your next birthday falls on, on every planet. Mercury birthdays come every 88 days. Saturn birthdays come about every 29 years. Most people only get two or three Saturn returns in a full lifetime. Most people never get a Neptune birthday at all.
How the site works
Everything runs in your browser. There is no backend, no account system, no analytics tracking individual users, no email collection, and no affiliate links. Your birthday is stored only in your device's local storage so the four calculators can share it without making you re-enter it. Nothing is sent to a server we control.
The site is funded entirely by display ads via Google AdSense. If you'd like to support Parallax without buying anything, turning off your ad blocker on this domain is the most useful thing you can do. We try to keep the ads quiet enough that you forget they're there.
Why do this?
The honest answer is that we wanted these tools to exist in a clean place. Most "age on Mars" calculators are buried inside spammy aggregator sites. The "life in weeks" visualization usually lives as a static image somewhere, with no way to enter your actual birthday. Time-use breakdowns get treated as productivity content when they're really closer to philosophy. Parallax collects the curiosity-shaped questions in one place — instant, private, and ad-light enough to read.
If a tool here ever changes a single decision you make today — a phone call you've been postponing, an hour you spend differently, a project you start sooner — it's done its job. Read more about the project →