Amortization calculator
Every payment, month by month: how much goes to interest, how much to principal, and what is left. Model extra payments on any schedule and rate changes on adjustable loans, or upload your payment history to see where you really stand.
Quick answer: A $300,000, 30-year loan at today's 7.24% Freddie Mac average costs $2,044 a month. The first payment is $1,810 interest and only $234 principal, and interest over the full 30 years totals $436,022.
By John Crane, MBA & the Editorial Team · Updated for the 2026 tax year. How we check our numbers
Monthly payment
$1,896.20
Principal and interest, 360 payments
| Principal | $300,000 | 43.9% |
|---|---|---|
| Total interest | $382,637 | 56.1% |
- Total interest
- $382,637
- Total of payments
- $682,637
- Payoff
- Dec 2055
- Payments
- 360
- Extra payments save
- -
- Time saved
- -
Balance over time
Amortization schedule
| No. | Date | Rate | Payment | Principal | Interest | Balance |
|---|---|---|---|---|---|---|
| 001 | Jan 2026 | 6.500% | $1,896.20 | $271.20 | $1,625.00 | $299,728.80 |
| 002 | Feb 2026 | 6.500% | $1,896.20 | $272.67 | $1,623.53 | $299,456.13 |
| 003 | Mar 2026 | 6.500% | $1,896.20 | $274.15 | $1,622.05 | $299,181.98 |
| 004 | Apr 2026 | 6.500% | $1,896.20 | $275.63 | $1,620.57 | $298,906.35 |
| 005 | May 2026 | 6.500% | $1,896.20 | $277.12 | $1,619.08 | $298,629.23 |
| 006 | Jun 2026 | 6.500% | $1,896.20 | $278.63 | $1,617.57 | $298,350.60 |
| 007 | Jul 2026 | 6.500% | $1,896.20 | $280.13 | $1,616.07 | $298,070.47 |
| 008 | Aug 2026 | 6.500% | $1,896.20 | $281.65 | $1,614.55 | $297,788.82 |
| 009 | Sep 2026 | 6.500% | $1,896.20 | $283.18 | $1,613.02 | $297,505.64 |
| 010 | Oct 2026 | 6.500% | $1,896.20 | $284.71 | $1,611.49 | $297,220.93 |
| 011 | Nov 2026 | 6.500% | $1,896.20 | $286.25 | $1,609.95 | $296,934.68 |
| 012 | Dec 2026 | 6.500% | $1,896.20 | $287.80 | $1,608.40 | $296,646.88 |
Where each year's payments go
How this is calculated
Each payment
Interest = balance × annual rate ÷ 12
The rest of the payment reduces the balance. Interest is rounded to the cent each month, the way lenders bill, and the final payment absorbs any rounding remainder so the balance closes at exactly zero.
Rate changes
When an adjustable rate resets, the remaining balance is re-amortized over the remaining term at the new rate, so the payment moves up or down. This is how standard ARMs adjust after the fixed period.
Extra payments
Extra money goes straight to principal. It stops that amount from accruing interest for the rest of the loan, which shortens the term. Savings are measured against the same loan with no extra payments.
Sources
Related guides
- When does PMI go away?The 80% and 78% rules for ending PMI, how long it takes, how extra payments and appraisals speed it up, and how FHA mortgage insurance differs.
- How mortgage amortization worksWhy early mortgage payments are mostly interest, the year principal overtakes interest, and how much extra payments save on a typical loan.
Questions
Why do early payments go mostly to interest?
Interest is charged on the remaining balance, which is largest at the start. As the balance falls, less of each payment goes to interest and more to principal, which is why the balance drops faster in later years.
Is one extra payment a year worth it?
On a 30-year mortgage, one extra payment a year cuts roughly four to six and a half years off the loan, more at higher rates (about 5.7 years at 6.5%). Enter it under Extra payments, Once a year, to see the exact savings for your loan.
How do I check my actual loan balance?
Open Your payments and upload your payment history (date and amount). The calculator replays every payment and shows your real balance, how it compares with the original schedule, and your payoff date.