Generate a full mortgage amortization schedule showing principal vs interest for every payment. See how extra payments save thousands in interest on any 30-year mortgage.
Full schedule with extra payment savings
| Year | Payment | Principal | Interest | Balance |
|---|
A mortgage amortization calculator reveals something most homeowners find surprising: on a $300,000 loan at 6.5%, your very first monthly payment of $1,896 sends roughly $1,625 to the lender as interest and only $271 toward actually paying down the principal. That ratio gradually flips over 30 years, but the early years are overwhelmingly interest-heavy. Viewing a full amortization schedule — every principal vs interest split, year by year — makes this stark reality visible and helps you plan extra payments strategically.
The loan payoff power of small extra payments is dramatic. On that same $300,000 / 6.5% / 30-year loan, paying just $200 extra each month cuts roughly 5.5 years off the loan term and saves over $60,000 in total interest. A one-time $5,000 lump sum early in the loan life saves far more than the same $5,000 paid in year 20, because interest compounds forward. Homeowners who refinance often use an amortization schedule to see exactly how many years of interest they are resetting — information that dramatically changes the math on whether refinancing makes sense.
In month one of a typical 30-year mortgage, 85%+ of your payment is pure interest. It takes about 18 years before your principal payment finally exceeds your interest payment each month.
Adding $100/month to a $250,000 loan at 6.5% saves roughly $33,000 in interest and cuts 3+ years off the term — without refinancing or changing your loan.
A 15-year mortgage at 6.0% on $300,000 costs $2,532/month but saves over $130,000 in interest vs a 30-year at 6.5%. Use the schedule to see exactly where that savings comes from.
If you refinance in year 5 of a 30-year loan, you reset to year 1 amortization on the new loan — meaning interest-heavy payments start again. The schedule helps you weigh that cost against rate savings.