The Big Mac Index is a global benchmark for measuring purchasing-power parity (PPP) — how far a currency’s money stretches in real-world terms — using one near-identical good sold the world over. Each day a scraper reads McDonald’s prices from third-party food-delivery apps across multiple cities in every tracked country, stores them, computes a city-level median, rolls those up to a national price, and derives a set of indices comparing each currency’s burger to this geometric mean global benchmark.