Balance is the starting point, not the answer
A bank balance can include money already assigned to bills, card repayments or planned purchases. It may also exclude valid credit-card spending that has not yet been repaid from cash.
Subtract committed money
Committed money covers obligations with limited flexibility: rent, loan payments, subscriptions, taxes, tuition or a card amount due. Treating it as spendable creates a predictable shortfall later.
Account for planned expenses
Plans are not identical to obligations, but realistic near-term costs still reduce freedom. Groceries, transport and household needs should be visible even when exact amounts can change.
Protect reserves
A reserve is deliberately excluded from everyday spending. Decide what the reserve protects and when it may be used; otherwise it becomes an unlabeled balance that disappears under pressure.
Include credit obligations without double counting
Count card purchases as spending when they occur, then treat repayment as settling the liability rather than creating another expense. The cash required for the due date still needs to be protected.