Working out a liveable wage takes a lot of data but it isn't that difficult to do.
Back in 1907, the Australian Court of Arbitration handed down a decision (the "Harvester Decision") that the minimum wage for an unskilled labourer in the Harvester machinery factory should be enough to support the worker and his family. The amount was seven shillings. It was calculated by adding up the costs of maintaining a family unit of the worker plus a wife and three children.
Harvester Case | Waltzing Matilda and the Sunshine Harvester Factory (fwc.gov.au)
This decision carried through to all wages in Australia where wages for skilled labour and various trades were seen as variation to the basic wage. The basic wage is adjusted annually taking into account inflation and things like productivity gains.
In Australia, minimum wage rates are set by a statutory body (the Fair Work Commission) independent of Parliament.
If Australia could do it in 1907 I'm sure it's not beyond the US in 2021.
OB