Amortization schedule calculator
Every mortgage payment is split between interest and principal, and early on the split is lopsided. Build the full schedule below, expand any year to see the individual payments, and test what an extra $100 or $500 a month actually buys you.
Scheduled principal & interest
$2,022.62
- Total interest paid
- $408,142
- Payoff time
- 30 yr 0 mo
- Total paid
- $728,142
Total cost split over the life of the loan
- Principal$320,00044%
- Interest$408,14256%
Add an extra monthly payment above to see how much interest and time it removes.
Payment schedule
Swipe the schedule sideways to see every column.
| Year | Interest | Principal | Balance |
|---|---|---|---|
| +Year 1 | $20,695 | $3,577 | $316,423 |
| +Year 2 | $20,455 | $3,816 | $312,607 |
| +Year 3 | $20,200 | $4,072 | $308,535 |
| +Year 4 | $19,927 | $4,345 | $304,191 |
| +Year 5 | $19,636 | $4,636 | $299,555 |
| +Year 6 | $19,325 | $4,946 | $294,609 |
| +Year 7 | $18,994 | $5,277 | $289,332 |
| +Year 8 | $18,641 | $5,631 | $283,701 |
| +Year 9 | $18,264 | $6,008 | $277,694 |
| +Year 10 | $17,861 | $6,410 | $271,284 |
| +Year 11 | $17,432 | $6,839 | $264,444 |
| +Year 12 | $16,974 | $7,297 | $257,147 |
| +Year 13 | $16,485 | $7,786 | $249,361 |
| +Year 14 | $15,964 | $8,308 | $241,053 |
| +Year 15 | $15,407 | $8,864 | $232,189 |
| +Year 16 | $14,814 | $9,458 | $222,732 |
| +Year 17 | $14,180 | $10,091 | $212,641 |
| +Year 18 | $13,505 | $10,767 | $201,874 |
| +Year 19 | $12,784 | $11,488 | $190,386 |
| +Year 20 | $12,014 | $12,257 | $178,129 |
| +Year 21 | $11,193 | $13,078 | $165,051 |
| +Year 22 | $10,317 | $13,954 | $151,097 |
| +Year 23 | $9,383 | $14,888 | $136,208 |
| +Year 24 | $8,386 | $15,886 | $120,323 |
| +Year 25 | $7,322 | $16,949 | $103,373 |
| +Year 26 | $6,187 | $18,085 | $85,289 |
| +Year 27 | $4,976 | $19,296 | $65,993 |
| +Year 28 | $3,683 | $20,588 | $45,405 |
| +Year 29 | $2,305 | $21,967 | $23,438 |
| +Year 30 | $833 | $23,438 | $0 |
Interest is calculated monthly on the outstanding balance. Taxes, insurance and mortgage insurance are excluded — this table covers principal and interest only.
How amortization actually works
A fixed-rate mortgage uses a level payment: the same dollar amount every month for the whole term. What changes is what that money does. The lender charges one month of interest on whatever you currently owe, and everything left over reduces the balance.
The arithmetic for a single month is short. Multiply the balance by the annual rate divided by twelve to get the interest. Subtract that from the payment. What remains is principal, and the new balance is the old balance minus that principal. Repeat 360 times and you have a 30-year schedule.
Worked example: $320,000 at 6.5% over 30 years
The scheduled principal-and-interest payment is $2,023. Here is how the same payment behaves at different points in the loan.
| Payment | Interest | Principal | Balance after |
|---|---|---|---|
| 1 (month 1) | $1,733 | $290 | $319,710 |
| 60 (year 5) | $1,633 | $390 | $300,955 |
| 120 (year 10) | $1,477 | $546 | $272,138 |
| 216 (year 18) | $1,110 | $913 | $204,015 |
| 300 (year 25) | $616 | $1,407 | $112,314 |
| 360 (year 30) | $11 | $2,012 | $0 |
Figures rounded to the nearest dollar. Total interest across the full term is about $408,000 — more than the amount borrowed.
The five-year equity problem
After 60 payments on that loan you have paid roughly $121,000 and reduced the balance by about $19,000. The rest went to the lender as interest. If you sell at that point, agent commission and closing costs can easily exceed the equity your payments built, which is why appreciation — not amortization — does most of the work for short-term owners.
This is also the practical argument for prepayment. A dollar of extra principal in year one removes every future interest charge that dollar would have generated for 29 years; the same dollar in year 25 removes almost nothing.
What extra payments do to the same loan
| Extra per month | Payoff | Total interest | Interest saved |
|---|---|---|---|
| $0 | 30 yr 0 mo | $408,142 | — |
| $100 | 26 yr 2 mo | $346,444 | $61,698 |
| $250 | 22 yr 3 mo | $285,148 | $122,994 |
| $500 | 18 yr 0 mo | $222,590 | $185,552 |
| $1,000 | 13 yr 2 mo | $156,743 | $251,399 |
Same $320,000 loan at 6.5%. Values produced by the calculator on this page; run your own numbers above to match your balance and rate.
Before you start paying extra
- Tell the servicer where the money goes. Unlabelled extra funds are often applied to next month's payment instead of principal. Most portals have an explicit “additional principal” field.
- Check for a prepayment penalty. Rare on modern conforming loans, but still present on some non-qualified and investor products. It appears in your note.
- Clear higher-rate debt first. Prepaying a 6.5% mortgage while carrying a 22% credit card balance is a guaranteed loss.
- Keep cash reserves. Money sent to principal is not accessible again without selling, refinancing or opening a home equity line.
Amortization questions
Why is almost all of my early payment going to interest?+
Interest is charged each month on the balance you still owe, and at the start you owe nearly the entire loan. On a $320,000 loan at 6.5%, the first month's interest is $1,733 of a $2,023 payment. As the balance falls, the interest slice shrinks and the principal slice grows — the split does not change because of any rule, only because the balance changed.
When does a 30-year loan cross the halfway point?+
On a 30-year fixed at typical rates, the payment splits evenly between interest and principal at roughly year 18, and you reach half the balance paid off at about year 21. That lag is why selling in year five returns far less equity than most buyers expect.
Does an extra payment reduce my monthly bill?+
No. Extra principal shortens the loan rather than lowering the payment. Your required payment stays the same; you simply reach a zero balance sooner. If you want a lower payment instead, you need a recast (some servicers offer it for a fee) or a refinance.
Is it better to pay extra monthly or make one lump sum a year?+
Monthly wins slightly because each dollar starts reducing interest earlier. The difference is small — on a $320,000 loan, splitting the same annual amount across 12 payments saves roughly a few hundred dollars more over the life of the loan than paying it in December.
What is a biweekly mortgage payment really doing?+
Paying half your payment every two weeks produces 26 half-payments, which equals 13 full payments a year instead of 12. The savings come entirely from that one extra payment, not from the biweekly timing. You can replicate it for free by adding one-twelfth of your payment to each monthly check.
Should I pay extra or invest the money?+
Paying extra earns a guaranteed, tax-free return equal to your mortgage rate. Investing may earn more but is not guaranteed. A common middle path is to fund an emergency reserve and any employer retirement match first, then direct surplus cash to the mortgage — prepaid principal is very hard to get back without selling or refinancing.
Need the full payment including taxes and insurance? Use the main mortgage calculator , or price an FHA loan with mortgage insurance included.
How these numbers are produced
The schedule uses the standard monthly amortization formula with interest compounded monthly on the outstanding balance. Extra payments are applied to principal in the month they are made, and the final payment is trimmed so the balance lands exactly at zero. Taxes, homeowners insurance, mortgage insurance and HOA dues are deliberately excluded here so the interest-versus-principal split stays readable.
Real servicer statements can differ by a few dollars because of rounding conventions, payment posting dates and daily-interest accrual on some products. Treat this as a planning tool and confirm payoff figures with your servicer before acting on them.