It depends on your loan amount and, even more, your interest rate. There's no single rule of thumb. The higher your rate, the more powerful an extra annual payment becomes, because each early dollar knocks out expensive interest and removes more time from the loan. At lower rates the same extra payment does less work and shaves off less. As a rough illustration, on a higher-rate loan one extra payment a year might take something like seven years off a thirty-year term. That number swings meaningfully with the rate and the balance, so treat it as a ballpark. The right way to know is to run it on your actual loan: your amount, your rate, your remaining term. Send us your numbers and we'll show you exactly what one extra payment a year, or any prepayment schedule you're considering, does to your payoff date and your total interest paid.