Answer: Enter your values and the Amortization Schedule Calculator returns the exact result instantly — formula, worked example, and a plain-English explanation are included below the tool.
Generate a full loan amortization schedule showing principal, interest, and balance for each payment.
| Month | Principal | Interest | Balance |
|---|
An amortization schedule is the month-by-month receipt for a loan: every payment split into its interest and principal parts, with the running balance after each one. The split is what surprises people. Early on, most of each payment is interest, because interest is charged on the outstanding balance and the balance is at its biggest before you've paid anything down. As the balance shrinks, the interest share falls and the principal share climbs, until the final payment is nearly all principal and the balance hits zero.
The payment itself comes from the standard amortization formula: M = P × [r(1+r)^n] / [(1+r)^n − 1], where P is the loan amount, r is the monthly rate (APR divided by 12), and n is the number of payments. The formula picks the one fixed payment that exactly zeroes the balance on payment n. This calculator applies it and then walks the schedule row by row: interest for the month equals balance times r, principal equals the payment minus that interest, and the new balance carries forward.
Enter those three numbers and the schedule shows a payment of about $1,580 a month, of which the very first one is $1,354.17 of interest and just $226.01 of principal. Roughly 86 cents of every early dollar is interest. Total interest over the 360 payments comes to about $318,900, meaning a quarter-million-dollar house costs about $568,900 with financing. Watch how the split travels across the life of the loan:
| Payment number | Interest portion | Principal portion | Remaining balance |
|---|---|---|---|
| 12 (year 1) | $1,339 | $241 | $247,207 |
| 60 (year 5) | $1,268 | $312 | $234,054 |
| 120 (year 10) | $1,148 | $432 | $211,924 |
| 180 (year 15) | $983 | $597 | $181,443 |
| 240 (year 20) | $754 | $826 | $139,169 |
| 300 (year 25) | $437 | $1,143 | $80,756 |
| 360 (final) | $9 | $1,571 | $0 |
Two readings worth taking from it. The crossover, where a payment's principal beats its interest, doesn't arrive until sometime between year 15 and 20 on this loan. And even after ten years of faithful payments, the balance has only fallen from $250,000 to about $212,000, which is why selling or refinancing early in a mortgage can feel like standing still.
The term of the loan sets the shape; the rate sets the price. On the same $250,000 over 30 years:
| Rate | Monthly payment | Total interest over 30 years |
|---|---|---|
| 5.0% | $1,342 | $233,138 |
| 6.0% | $1,499 | $289,593 |
| 6.5% | $1,580 | $318,861 |
| 7.0% | $1,663 | $348,774 |
| 8.0% | $1,834 | $410,388 |
Each point of rate is worth roughly $65,000 to $70,000 of interest on this loan. That's why rate shopping matters more than almost any negotiation in the purchase, and why our guide on how to calculate a mortgage payment spends as much time on the rate as the formula.
A 15-year schedule at the same 6.5% runs a $2,177 payment on this loan but pays only about $142,000 of interest, a saving of roughly $177,000 versus the 30-year path. The gentler alternative is extra principal: adding just $100 to each monthly payment on the 30-year loan retires it about 4½ years early and saves around $58,000 in interest. Extra payments don't lower the required amount; they erase future interest, because every prepaid dollar stops generating its monthly rent. The extra payments payoff guide works through the math loan-first, and the mortgage calculator prices the full picture with taxes and insurance factored in.
The same engine drives every fixed installment loan, not just mortgages. A car loan or personal loan follows the identical schedule logic with a smaller n, which is why the balance drops so much faster on a 60-month auto loan than on a 360-month mortgage. Generate a schedule above for any combination and watch the curve bend.
A loan is amortized when it's repaid by fixed payments on a set schedule, with each payment split between interest and principal in a way that zeroes the balance on the final payment. Mortgages, auto loans, and personal loans are typically fully amortizing. Credit cards are the common exception: their revolving minimum payments don't follow a fixed payoff path.
Interest is charged on the outstanding balance, and the balance is at its biggest before you've paid anything down. On a $250,000 loan at 6.5%, the first payment includes about $1,354 of interest and only $226 of principal. As the balance shrinks, each payment's interest share falls and the principal share rises, until the final payment is nearly all principal.
Every extra dollar sent toward principal kills all future interest that dollar would have generated. On a $250,000 loan at 6.5% over 30 years, adding $100 to each monthly payment retires the loan roughly 4½ years early and saves about $58,000 in interest. Extra payments don't lower the required payment; they shorten the loan and cut total interest.
Yes, and that's the hidden cost of restarting a 30-year loan after years of payments. A new 30-year term puts you back at the interest-heavy beginning of the curve, which can raise lifetime interest even at a lower rate. Refinancing into a shorter term, or keeping the payoff date the same as the original schedule, avoids the reset.