Savings Rate

Your savings rate is the share of income you don't spend — the single most predictive number in personal finance. It beats investment returns over the medium term because you control it completely: raising a savings rate from 10% to 20% roughly halves the time to financial independence, while a 1% better return barely moves it. Measure it on gross income for a strict version, or on take-home pay for a practical one, but measure it the same way every month.