The annual salary in the calculator goes up to $140,000 for the US. This needs to be way higher if we're talking Bay Area.
Average for senior engineers is around $200K, upper limit towards $300K.
Why not just make it open to typing in the sum, at least optionally?
Median base salary at google is 149, and there are plenty of offers in the 200-400 range with outliers well above that. From personal experience 140 is on the low range for 3 years experience in the major US tech markets (Seattle, Bay, Austin)