The amount is highly personal but I’ll say that its based mostly on these variables:

• Fixed predictable expenses (mortgage, car payments, healthcare, taxes)

• Variable but fairly predictable expenses (food, unexpected maintenance and other such stuff)

• Money for occasional investments when I spot “a deal” on a stock of interest

• Slush in case of crash, zombies, and/or Terminators

I use the previous year’s statements and taxes to find the number that feels most comfortable. For some, my % would be too high and for others too low, but we all have our own Goldilocks zones.

Not all of that is in cash, really. Chunks are in CDs where they can earn more but are more easily cashed out for an emergency.