The ratio of active priests to active laypeople in the US is really bad. Seven times worse than the Orthodox ratio.
For Catholics, there's 1 active priest for every 441 regular massgoers. For Orthodox, that ratio is about 1 for every 65 regular liturgy attendees.
I've calculated the numbers using data from Georgetown's CARA, official Orthodox Church in America clergy numbers, and the US Religion Census.
The formula for Catholics was (Parish-connected Catholics x Percentage of Catholics who attend Mass every week) / ((Total diocesan priests x percentage of diocesan priests active in ministry) + total religious priests). There isn't easily accessible data on the percentage of religious priests who are active, so the ratio I calculated actually looks better than it really is.
Formula for Orthodox was straightforward (active priests / number of regular attendees).