The gap exists because profit is recorded when work is done and cash moves when somebody pays. A business can invoice twelve thousand in a month, show a healthy profit, and hold four thousand in the bank because most of it is still outstanding. Taking a draw against that profit means spending money you have not received.
Start with the balance and subtract what is already committed. Supplier bills due in the next few weeks. Tax set aside but not yet paid. Card balances. Payroll if anybody else is involved. Anything you have been paid for but not yet delivered, which is somebody else's money until the work is done. What remains after those is the figure to consider.
Then subtract your operating float. Every business needs an amount below which it cannot function comfortably, and that number should be decided in advance rather than discovered. For most first year businesses one month of fixed costs is the minimum and three is more comfortable.
The taxes point is where most owners get caught. Money collected as sales tax was never yours, and income tax on profit is due whether or not the cash is still in the account. Both should be moved to a separate account as they arise rather than calculated at the deadline, which is the single most useful cash habit a young business can adopt.
Pay yourself consistently rather than opportunistically, which is the harder discipline and the more useful one. A regular modest draw is easier to plan around than an irregular large one, it tells you honestly whether the business can support you, and it prevents the pattern where good months are spent and bad ones are absorbed personally.
Treat your own pay as a cost rather than as what remains. A business that only pays its owner from leftovers is not profitable, it is subsidised, and the profit and loss statement will not say so unless your pay appears as an operating expense. That single change reveals whether the business actually works.
Build a short rolling forecast covering the next three months, updated weekly. Opening balance, expected receipts, known payments, closing balance, carried forward. It takes minutes once it exists and it answers this question directly, which no other document does.
Watch the closing balance against your minimum rather than watching for zero. The week it drops below your floor is the week to act, and acting early means chasing an invoice or delaying a purchase rather than borrowing at short notice.
Where the honest answer is that you cannot pay yourself this month, that is information worth acting on rather than absorbing quietly. Repeated months of it means the pricing is wrong, the payment terms are wrong, or the volume is not there. All three are addressable, and none of them get addressed while the shortfall is being covered from personal savings without being named.
Decide your minimum balance in advance and write it down, because deciding in the moment produces a number that conveniently matches what you want to take. One month of fixed costs is the floor and three is more comfortable.
Review the draw quarterly rather than adjusting it monthly. A figure that moves with every good and bad month is impossible to plan around personally, and the point of paying yourself consistently is that both you and the business can rely on it.