Amortization Calculator
Calculate your fixed monthly loan payment, total interest, total of all payments, and payoff date from a loan amount, interest rate, and term.
Calculator Inputs
Sets the currency this calculator's numbers are denominated in. This is presentation only — it does NOT convert your numbers between currencies, it only changes how they're formatted.
The total amount you're borrowing (original principal).
The loan's nominal annual interest rate (e.g. 6 for 6%). Not an effective/compounded rate.
Whole years of the loan term. Combine with months below for a term like 5 years 6 months.
Additional months (0-11). For 18 months, enter 1 year 6 months.
The loan's origination month. Used only to label which calendar month each payment falls in — it does not change the payment math.
The loan's origination year. Used only for calendar labeling, alongside Start Month.
- Monthly Payment
- $1,498.88
- Total Principal
- $250,000.00
- Total Interest Paid
- $289,593.37
- Total of All Payments
- $539,593.37
- Number of Payments
- 360
- Estimated Payoff Date
- January 2056
Full Amortization Schedule
All 360 monthly payments, from February 2026 to January 2056.
Remaining Balance by Year
Estimated remaining loan balance at the end of each year (every 12th monthly payment), sampled from the full monthly schedule above — not a separate calculation.
About these results
CalcSpectrum calculators produce automated estimates using established formulas and the specific values you enter. Because real-world outcomes depend on input accuracy, mathematical assumptions, and rounding conventions, please verify critical figures with an appropriately qualified financial, tax, medical, legal, or other professional, as relevant.
Financial Notice: These figures are informational estimates for personal planning only. They do not constitute financial, investment, tax, or legal advice, nor do they represent a lending offer or credit approval. Provider and financial institution figures, rates, fees, and underwriting requirements may differ.
How It's Calculated
Formula
An amortization schedule breaks every loan payment into its two components — interest and principal — for every period of the loan's life, from the first payment to the last. This calculator computes the full monthly schedule internally from your loan amount, interest rate, and term, using the standard fixed-rate (ordinary annuity) amortization formula: it solves for the constant monthly payment that pays off the loan's principal exactly by the final payment. Early in the schedule, most of each payment goes toward interest, because interest is charged on a still-large remaining balance; as the balance shrinks month by month, a growing share of the fixed payment goes toward principal instead, until the very last payment finishes paying off whatever balance remains. The Start Month and Start Year fields don't change any of that math — they only label which calendar month each payment falls in, so "Payment 1" can be shown as, say, "April 2026" instead of an anonymous number. Per the standard ordinary-annuity convention, the first payment is due one full calendar month after the start month/year you enter (so a March 2026 start means payment 1 is due April 2026, and a December 2026 start rolls over to January 2027).
Worked Examples
$250,000 loan, 6% annual rate, 30-year term (starting March 2026)
- Principal P = $250,000, annual rate 6% → monthly periodic rate r = 0.06 / 12 = 0.005
- Term: 30 years → n = 360 monthly payments
- Fixed monthly payment = P × r × (1+r)^360 / ((1+r)^360 − 1) = $1,498.88
- Schedule excerpt (Month, Interest, Principal, Ending Balance):
- Payment 1 (April 2026): interest $1,250.00, principal $248.88, balance $249,751.12
- Payment 2 (May 2026): interest $1,248.76, principal $250.12, balance $249,501.00
- Payment 3 (June 2026): interest $1,247.51, principal $251.37, balance $249,249.63
- Payment 180, the halfway point (March 2041): interest $891.14, principal $607.74, balance $177,621.13 — notice interest is already well below the principal portion by the midpoint
- Payment 360, the final payment (March 2056): interest $7.44, principal $1,488.01, balance $0.00 — the final payment's principal is set to exactly whatever balance remains, so the schedule always reconciles to a precise $0.00
- Totals over the full term: total principal = $250,000.00 (equals the original loan amount), total interest ≈ $289,593.37, total of all payments ≈ $539,593.37
$60,000 loan, 5% annual rate, 10-year term (starting January 2026)
- Principal P = $60,000, annual rate 5% → monthly periodic rate r = 0.05 / 12 ≈ 0.0041667
- Term: 10 years → n = 120 monthly payments
- Fixed monthly payment = P × r × (1+r)^120 / ((1+r)^120 − 1) = $636.39
- Payment 1 (February 2026): interest $250.00, principal $386.39, balance $59,613.61
- Payment 60, the halfway point (January 2031): interest $142.57, principal $493.82, balance $33,723.13
- Payment 120, the final payment (January 2036): interest $2.64, principal $634.20, balance $0.00
- Total interest over the full term ≈ $16,367.25 — a shorter term and lower rate than the first example mean far less total interest, even though the payment is a much smaller monthly amount
Frequently Asked Questions
Why does most of my early payments go toward interest instead of principal?
Interest for each payment is calculated on the balance still owed at that point, not on the original loan amount. Early on, the balance is close to the full loan amount, so the interest portion is largest. Every payment is the same fixed amount, so whatever's left after interest goes to principal — which is small at first and grows every month as the balance (and therefore the interest charge) shrinks.
Does the Start Month/Start Year change my payment amount?
No. Start Month and Start Year only affect the calendar labels shown for each payment (which month a given payment falls in) — they have no effect on the payment amount, the interest/principal split, or the total interest paid. The payment math depends only on loan amount, interest rate, and term.
Why is my first payment dated the month after my start month?
This follows the standard "ordinary annuity" convention used for virtually all conventional loans: a payment is due at the END of a period, not the beginning. If your loan originates in March, the first full month of interest accrues during March, and that first payment becomes due at the end of that period — labeled as April. A December origination rolls over into a January first payment the following year.
Why does the last payment amount look slightly different from the others?
This calculator's schedule reconciles to an exact $0.00 final balance, matching how real bank and lender amortization statements are produced: every row's interest and principal are rounded to the cent, and the final payment's principal is set to whatever balance is actually left (rather than the formulaic payment-minus-interest amount), so tiny rounding differences don't accumulate into a balance that never quite reaches zero. The result is a final payment that may differ from the regular payment by a few cents to a couple of dollars — a normal, expected "true-up" payment.
Can I see the full month-by-month schedule, not just an excerpt?
Yes. The full schedule — every payment, with its date, payment amount, principal, interest, and remaining balance — is available below the summary results. For a long-term loan it's collapsed by default ("View full schedule") so the page doesn't load hundreds of rows before you've asked for them; click it to see every row.
Does this work for any type of fixed-rate loan?
Yes — the underlying fixed-rate amortization math is the same one used for mortgages, auto loans, and personal loans. This calculator assumes monthly payments with no extra payments, fees, taxes, or insurance folded in; for mortgage-specific extras like property tax and homeowners insurance, use the dedicated Mortgage Calculator instead.