You'll often see financial advice websites claim that one extra mortgage payment a year will reduce your loan term by 11-12 years on your 30 year mortgage. This was technically true for a brief period in the 1980s. Not sure why this ephemeral factoid made it's way on the the early web and survived as it became less and less true over the years, but I guess it dove tails nicely with the other nonsense about the "huge tax savings" from deducting your mortgage interest*

*Was still sort of true if you had a VERY expensive house.

My parents paid their house off after 7 years, but that is quite a lot easier to do with most of your payment is high interest rates and you have a much smaller principle to attack.