The Economist has a famous index – the Big Mac Index – which compares what Big Macs cost around the world, converted to US dollars. It’s designed to measure whether currencies are under- or over-valued compared to the US dollar. The idea is that because Big Macs are a standardised product, comparisons should be fair.
A different take on Big Macs is to look at food inflation. Let’s say you are an average wage earner. For 1 month there are no taxes or property costs and you spend all your wages on Big Macs. How many Big Macs would you have bought 10 years ago? How many would you buy now? For most countries - fewer Big Macs than 10 years ago. In most countries food has become more expensive. Exceptions are the United States and Canada, which have have relatively bigger agricultural production and lower energy prices than many other countries.
(Sources: ILO wages report, Big Mac Index:github.com/TheEconomist/big-mac-data)