There's nothing worse than seeing an entrepreneur walk away from her business because she didn't create a long enough financial runway. It's easy to see people on social media flaunting their overnight success and assume that's the norm. I think 6-12 months is more realistic. To that I would suggest: Have 3-6 months of savings set aside to alleviate the financial stress of not having a regular income. Also, make sure your spouse/partner is on board if it takes 6 months or longer to generate income. An honest discussion today can prevent arguments down the road. Be sure your idea/product will sell. A friend's opinion doesn't count. If you can get financial buy in before leaving your day job, even better. Most new entrepreneurs invest heavily in the nice business cards, website, and branding before they've sold anything. This eats up your precious resources and it's not the reason people will buy from you. You brand will go through many iterations so spend minimally here in the beginning. Bolster your financial runway today and you'll give yourself the breathing room and timeline to grow your business.