Reviewed by LoanCalcly Editorial · Published September 20, 2026
What the table is actually showing
A fixed-rate loan has a constant payment, which hides a moving structure. Interest is charged as the rate applied to the balance you still owe, so it is largest at the start and falls every month. The payment is fixed, so whatever is left after interest goes to principal — which means the principal portion grows every month.
Monthly payment = Interest on the current balance + Principal reduction
That single sentence explains everything the table shows. Here is the first year of a $300,000 loan at 6.5% over 30 years:
| Month | Payment | Principal | Interest | Balance |
|---|---|---|---|---|
| 1 | $1,896.20 | $271.20 | $1,625.00 | $299,728.80 |
| 2 | $1,896.20 | $272.67 | $1,623.53 | $299,456.12 |
| 3 | $1,896.20 | $274.15 | $1,622.05 | $299,181.97 |
| 4 | $1,896.20 | $275.64 | $1,620.57 | $298,906.34 |
| 5 | $1,896.20 | $277.13 | $1,619.08 | $298,629.21 |
| 6 | $1,896.20 | $278.63 | $1,617.57 | $298,350.58 |
| 7 | $1,896.20 | $280.14 | $1,616.07 | $298,070.44 |
| 8 | $1,896.20 | $281.66 | $1,614.55 | $297,788.79 |
| 9 | $1,896.20 | $283.18 | $1,613.02 | $297,505.60 |
| 10 | $1,896.20 | $284.72 | $1,611.49 | $297,220.89 |
| 11 | $1,896.20 | $286.26 | $1,609.95 | $296,934.63 |
| 12 | $1,896.20 | $287.81 | $1,608.40 | $296,646.82 |
Payment $1,896.20 throughout. The principal column grows by a little more each month, the interest column falls by the same amount.
Notice what twelve months of $1,896.20 payments achieved: $22,754 paid, $19,401 of it interest, and a balance down by $3,353. After a year of paying on time, 85% of the money went to interest and 1.1% of the loan was repaid. This is not a malfunction — it is what a 6.5% rate on a large balance does in year one.
Thirty years in seven lines
The same loan, summarised year by year. Read down the interest column: it falls slowly at first, then collapses.
| Year | Principal repaid that year | Interest that year | Balance at year end |
|---|---|---|---|
| 1 | $3,353 | $19,401 | $296,647 |
| 5 | $4,346 | $18,409 | $280,833 |
| 10 | $6,009 | $16,745 | $254,328 |
| 15 | $8,310 | $14,445 | $217,677 |
| 20 | $11,491 | $11,263 | $166,996 |
| 25 | $15,890 | $6,864 | $96,912 |
| 30 | $21,973 | $781 | $0 |
$300,000 at 6.5% over 30 years. Figures rounded to the nearest dollar.
Two things stand out. First, total interest of $382,633 — on a $300,000 loan, you pay more in interest than you borrowed. That is the arithmetic of 6.5% over thirty years, and it is why term choice dominates rate shopping; comparing offers on rate alone will miss it.
Second, look at the pacing. By the end of year 10 you still owe $254,328 — five-sixths of the loan after a third of the term. The principal overtakes interest for the first time in month 233, more than nineteen years in. If you plan to sell or refinance inside five years, year one of this table is close to the whole story, which is exactly why break-even maths matters more than the headline saving.
What an extra payment does
Extra money paid to principal does not reduce the scheduled payment. It removes months from the end of the loan, and every month removed is a month of interest that never gets charged:
| Extra per month | Months | Loan ends | Total interest | Interest saved | Time saved |
|---|---|---|---|---|---|
| $0 | 360 | 30 years | $382,633 | — | — |
| $100 | 312 | 26 years | $321,639 | $60,995 | 4 years |
| $200 | 277 | 23 years 1 month | $279,185 | $103,449 | 6 years 11 months |
| $500 | 210 | 17 years 6 months | $202,874 | $179,759 | 12 years 6 months |
$300,000 at 6.5% over 30 years, no lump sums. Assumes no prepayment penalty.
Three ways to use a schedule before you commit
Check the balance at your realistic exit point
Most loans are not held to term. Find the row for the month you expect to sell or refinance and read the balance. That is what you would need to clear from the sale — and it is the number, not the monthly payment, that determines whether the deal was a good one. On the loan above, selling in year five leaves $280,833 outstanding.
Test the term before you choose it
Change the term and watch two things: the payment, and the year the principal column overtakes the interest column. A 15-year loan reaches that crossover far earlier, which is the mechanical reason shorter loans build equity so quickly — the amortization guide works through the full comparison.
Price the prepayment decision honestly
Extra payments produce a guaranteed return equal to your interest rate and are irreversible once made. That is a real trade against keeping the cash liquid, and it deserves to be made deliberately rather than as a reflex. Before committing, check three things:
- No prepayment penalty. Most fixed-rate instalment loans do not have one, but the minority that do can make overpayment counterproductive.
- An emergency fund in place first. Money paid to principal is hard to get back; money in a savings account is not.
- Whether forgiveness is in play. On a loan heading for an income-driven forgiveness, extra payments reduce what would have been forgiven and can return nothing at all.
For a mortgage payment that includes tax and insurance rather than principal and interest alone, use the mortgage calculator.
Frequently asked questions
What is an amortization schedule?
A table showing every payment on a fixed-rate loan split into its two parts — the interest charged that period and the principal it reduces — and the balance remaining afterwards. Because the payment stays the same while the balance falls, the interest portion shrinks and the principal portion grows over the life of the loan.
Why is so much of my early payment interest?
Because interest is charged on the balance and the balance is still large. On a $300,000 loan at 6.5%, the first payment of $1,896.20 contains $1,625 of interest and only $271.20 of principal. There is nothing unfair about it: the interest is simply the rate applied to what you still owe. It also means payments made early are the most powerful ones you will ever make.
How much does an extra payment save?
More than most people expect, because the saving compounds over the remaining term. On a $300,000 30-year loan at 6.5%, an extra $200 a month finishes the loan about seven years early and removes roughly $103,000 of interest. The same $200 paid in year 25 would save a fraction of that.
Do extra payments reduce my monthly payment?
Normally no — they shorten the term instead. On a standard fixed-rate instalment loan the scheduled payment is fixed by the contract; extra principal simply moves the payoff date forward. Some lenders offer to recast the loan and reduce the payment instead, which usually requires a fee and an application.
Can I use this for any type of loan?
Yes, for any fixed-rate fully amortising loan — mortgages, car loans, personal loans, student loans. It does not model interest-only periods, adjustable rates, or loans where the payment is recalculated each year. For a mortgage payment including tax and insurance, use the mortgage calculator instead.
Other calculators
- Mortgage calculator — Monthly payment with property tax, home insurance, HOA and PMI folded in — the number that actually leaves your account, not just principal and interest.
- Auto loan calculator — Work out the amount financed from price, down payment, trade-in and sales tax, then see what the monthly payment really costs over 48, 60 or 72 months.
- Personal loan calculator — Unsecured borrowing at the rates lenders actually quote, with the origination fee maths that decides whether the money is worth taking.
- Student loan calculator — Payment and total interest on a student loan, plus what a modest extra monthly payment does to the payoff date — the cheapest interest saving there is.
Guides that go with it
- How loan amortization works — The formula term by term, a worked month-by-month example, when principal finally overtakes interest, and why extra early payments save so much.
- How to compare loan offers — Why the headline rate is not the comparison, the three numbers that are, and how to work out whether discount points are worth paying.
- APR vs interest rate — What each number actually measures, what APR leaves out, and the cases where comparing APR will lead you to the wrong lender.
This calculator is educational and is not financial advice, and its output is an estimate — lenders apply their own fees, rounding rules and day-count conventions. Every figure was produced by the same calculator code and independently recomputed before publication. Spot an error? Tell us — see also our disclaimer.