The short answer
Most of your early mortgage payments go to interest because interest is charged on what you still owe, and at the start you owe nearly everything. On a $400,000, 30-year loan at 6.5%, about 85% of the first year's payments go to interest. That's what we call the 85% problem. More of each payment goes to principal over time, but on this loan, principal doesn't overtake interest until year 20.
The 85% problem
Picture your first mortgage payment. You send $2,528 to the bank. You'd expect a good chunk of that to come off your balance.
Here's what actually happens. The bank takes 6.5% a year on $400,000, which works out to $2,167 for the month. That comes off the top. The remaining $362 goes to your balance.
So after your first payment, you owe $399,638. After a full year of payments, $30,339 in total, you owe $395,529. You paid $25,868 in interest and knocked $4,471 off the loan.
About 85% to the bank, 15% to the house. That's the 85% problem, and every 30-year mortgage at rates like these has a version of it.
How amortization works
Amortization is the name for paying off a loan with equal payments over a set time. Your payment never changes on a fixed-rate loan. What changes is the split inside it.
Each month, the math goes in the same order:
- The lender calculates interest on your current balance.
- Your payment covers that interest first.
- Whatever is left reduces your balance.
Next month, the balance is a little smaller, so the interest is a little smaller, so a little more goes to principal. The shift is slow at first and fast at the end. It's like pushing a car: hard to get moving, easy once it's rolling.
The 85% problem, year by year
Here's the full picture on a $400,000, 30-year mortgage at 6.5%, with a fixed payment of $2,528:
| Year | Interest paid that year | Principal paid that year | Share going to interest | Balance at year end |
|---|---|---|---|---|
| 1 | $25,868 | $4,471 | 85% | $395,529 |
| 5 | $24,545 | $5,794 | 81% | $374,444 |
| 10 | $22,327 | $8,013 | 74% | $339,105 |
| 15 | $19,259 | $11,080 | 63% | $290,237 |
| 20 | $15,018 | $15,322 | 49% | $222,661 |
| 25 | $9,152 | $21,187 | 30% | $129,217 |
| 30 | $1,042 | $29,298 | 3% | $0 |
Two numbers in this table deserve a second look.
Year 15. Half the loan term is gone, and 73% of the balance is still there.
Year 20. This is the first year more of your payment goes to the house than to the bank. The exact crossover is payment number 233, about 19 years and 5 months in.
Why lenders aren't cheating you
It's easy to read that table and feel cheated. You aren't. The bank is charging the same rate every month on whatever you owe. It just happens that you owe a lot for a long time.
That's also why the 85% problem has a simple fix. Lower the balance sooner, and every future month charges interest on a smaller number. A free payoff projection shows exactly where your own loan sits on this curve.
How to beat the 85% problem
Every extra dollar you pay toward principal early in the loan does two things. It lowers your balance today. And it lowers the interest charged on every payment for the rest of the loan.
That's why small extra payments do so much. An extra $100 a month on our example loan saves about $63,900. An extra $500 a month saves about $205,600 and ends the loan in 19 years and 5 months, right around the point where a normal schedule would only be reaching its crossover. See extra mortgage payments for the full table.
If you want to get more aggressive, paying off a 30-year mortgage in 10 years shows what it takes. And for every option ranked side by side, start with how to pay off your mortgage faster.
What this means for your total interest
Because interest is front-loaded, the total adds up fast. On our example loan, you'd pay $126,140 in interest in the first five years alone, and $510,178 over 30 years. See how much interest you'll pay on a 30-year mortgage for totals at other rates and loan sizes.
A different way around the problem
Extra payments fight the 85% problem with more money. Ridgewell's Mortgage Accelerator Program is designed to change the structure itself, so less of each dollar you already earn goes to interest. For qualifying households, it is designed to pay off a home in as little as 5 to 7 years.
Payoff timelines are illustrations for qualifying households and are not guaranteed.
It also matters what happens to your family if your income stops partway through all those years of payments. That's what mortgage protection covers.
Where to start
Find where you are in your own loan. Look at your latest statement and check how much of last month's payment went to interest. If it's more than half, you're still early enough for extra payments to make a big difference.
Then get a free payoff projection. A licensed agent will show you your current schedule and what's possible with your real numbers, in about 15 minutes.
All examples assume a $400,000, 30-year fixed mortgage at 6.5%, principal and interest only, with figures rounded.
