100k in San Francisco is tight, especially if you want to live alone in a desirable neighborhood. After taxes, you're probably looking at around $6,000 a month. Rent for a decent one-bedroom apartment could easily be $3,000+. Factor in utilities, groceries, transportation, and other expenses, and you're not left with a ton of disposable income. It's doable, but you won't be living large. Consider negotiating for more, or looking at roommates/living in a less expensive neighborhood.