When to quit your job
Quit when you have a repeatable dollar and a validated lead source, not when you have saved a particular number. Runway buys time; pipeline ends the problem. Most people leave too early on savings or too late on comfort.
The savings mistake
The standard advice is six months of expenses. It sounds prudent and it answers the wrong question.
Savings sets a deadline. It does nothing about where clients come from, which is the actual problem, and the deadline arrives whether or not you have solved it. Six months of runway with no pipeline is six months of increasing pressure ending in whatever work you can get at whatever price.
The three conditions
Repeatable income. Money that recurs without starting from zero. One large project is an event; two retainers are a pattern.
A named lead source. Specifically where the next client comes from, with a track record. "Referrals" describes a hope. "Two partners who have each sent me a qualified lead a month for four months" describes a channel.
It covers real costs. Actual monthly outgoings, including tax and annual bills divided by twelve — usually twenty to thirty percent higher than people estimate. See the replacement number.
Hold all three for three consecutive months. Three months distinguishes a pattern from a run of luck.
Build it while employed
Every condition can be met before you resign. Evenings and weekends are enough to reach a repeatable dollar in most service businesses, and doing it in that order means you find out whether the thing works while you still have income.
The objection is that it is slower. It is, and that is the price of not discovering the offer was wrong during the month your savings ran out. See the exit pipeline.
A worked example
Two people each have twelve months of savings and want to go independent.
The first quits on the savings alone. It takes four months to land a first client, and by then the pressure is showing up in every sales call. The runway was real, but it was being spent to discover whether anyone would pay at all.
The second keeps the job and takes two small paid projects on evenings and weekends, both from referrals. Having been paid twice from one source, she knows what the offer is worth and where the next client comes from. She leaves with the same savings, a price and a pipeline, and the savings become a cushion rather than a countdown.
When to go sooner
Two cases. If the job is actively damaging you, the calculation changes and the cost of staying is not financial. And if you have a contract signed that covers costs for a year, the validation has already happened.
Everything else is the three conditions. See the 25-vs-45 asymmetry.
Questions
When should you quit your job to start a business?
When repeatable income covers your real monthly costs, from a lead source you can name specifically, sustained for three consecutive months.
How much savings do you need to quit your job?
Savings matter less than pipeline. Runway sets a deadline without solving where clients come from, and the deadline arrives whether or not the problem is solved.
Can you build a business while employed?
In most service businesses, yes. Evenings and weekends are enough to reach repeatable income, which lets you test whether the offer works while you still have a salary.