Have you breathed the same air as the President today?
We combine your location, today's wind, and the President's last reported whereabouts to calculate your odds.Many people are saying it's the best calculator.
Locating the President…
The President You, at the centre
Your browser will ask for your location. It stays on your device; we only use it to measure distance and wind direction.
Warming up the jet stream…
The actual science (spoiler: over a lifetime, everyone is tier 10)
A person exhales roughly 7 liters of air a minute. Over a lifetime that's about 7 × 10³⁰ molecules. The atmosphere holds about 10⁴⁴ molecules and mixes globally within a year or two, and nitrogen, 78% of what we exhale, doesn't get used up.
So every breath you take contains on the order of a billion molecules once exhaled by any given long-lived adult, the President included.
Today's odds are a different question: could air he exhaled in the last day have reached you? Wind at ground level carries air a few hundred kilometers (a couple hundred miles) a day, so we use his last reported location, today's wind there, and your distance to estimate that. The tiers are for fun. The billion molecules are real.