How does an increase in USD money supply affect inflation? Say an average american household is bringing in $50,000 a year.
Between ongoing quantitative easing and the drastic stimulus packages passed in February-May 2020, the USD Money Supply increased by 25% or 16% depending on if you look at M1 or M2, respectively. (I assume M2 is more directly related to inflation, but would love if anyone can provide clarity there)
Assuming 0 change in real output (not likely, but for simplicity) would the last 3 months actions to increase the money supply equate to a direct equivalent loss of value per USD?
Would this average American family's \$50,000/yr income in February become equivalent to a \$42,000/yr salary(in Feb \$'s) by May?
Or are there other factors in play? (outside increasing real output)
Adding this question and its answers as they're relevant here.
Yes there are other factors at play. Inflation is change in a price level. The price level, according to classic textbook monetary equation, is determined as follows:
$$P = \frac{MV}{Y}$$
Where $M$ is the money supply, $V$ velocity of money (how much is one dollar used in the economy) and $Y$ is the real output.
So beside money supply and real output inflation depends also on velocity of money. Furthermore, the inflation also depends on peoples expectations of these quantities. That is on what people expect the money supply, real output and velocity will be (although this is not shown in the simplified textbook model above).

Would this average American family's \$50,000/yr income in February equivalent to a \$42,000/yr salary in May?

Not likely. According to the International Monetary Fund the the annual inflation forecast for USA for 2020 and 2021 is $0.6\%$ and $2.2\%$ respectively. These are mean forecasts so of course the actual realized values will not be exactly the same, but I would be surprised if even $99\%$ confidence interval would even include double digit inflation. The assumption that output does not change is currently also not realistic. USA lost $6\%$ of GDP just in 2020Q1 according to the Bureau of Economic Analysis and the fall for Q2 is projected to be even worse.