According to the wikipedia page on ATP, the average ATP concentration in eukaryotic cells is 1 to 10 micromols per gram.

According to https://bionumbers.hms.harvard.edu/bionumber.aspx?s=n&v=2&id... a single mammalian cell has a mass of 3 to 4 nanograms.

Google AI tells me the average rate of ATP formation in a mammalian cell is around 10 million molecules per second.

The ratio here ranges from 3 to 40 minutes.

I imagine it varies greatly depending on cell type.