Here’s a hand-wavy estimate. Last year, the personal savings rate in the US was about 8%, so at that rate it would normally take 12.5 years to accumulate 1 year

Here’s a hand-wavy estimate. Last year, the personal savings rate in the US was about 8%, so at that rate it would normally take 12.5 years to accumulate 1 year’s income worth of savings, or 6.25 years to save 6 months. If you earned 10% more and saved all of it, and didn’t change anything else about your spending or saving, then your new savings rate would be 16.3%, which would mean it’d take a little over 3 years to save for 6 months. If you previously weren’t saving anything, but you started saving all the extra income from a 10% raise, then your savings rate would be ~9% and it’d take you 5.5 years to save 6 months’ worth of income.