Amortization Schedule
See exactly how each monthly payment splits between principal and interest over the life of your loan. Enter your loan amount, interest rate, and term to generate a detailed amortization schedule with yearly summaries.
Amortization is how a fixed-rate loan gets paid off: every payment is the same dollar amount, but the split between principal and interest changes over time. Early in the loan, when the balance is large, most of each payment is interest. Late in the loan, when the balance is small, most of each payment is principal. The amortization schedule is the month-by-month table that makes this split visible.
This calculator takes a loan amount, rate, and term, and produces a complete amortization schedule with monthly principal/interest splits and yearly summaries. It works for any fully amortizing fixed-rate loan: mortgages, auto loans, student loans (most), personal loans, business term loans.
Looking at the schedule reveals a counterintuitive fact: on a 30-year mortgage at 6.5%, you don't actually pay off half the original principal until about year 22. The early years are dominated by interest. This is why mortgage interest deductions are largest in the first decade and why prepayments early in the loan have outsized impact.
Inputs
Results
Monthly Payment
$1,580
Total Payments
$568,861
Total Interest
$318,861
Balance Over Time
Principal vs Interest
Yearly Summary
| Year | Total Payments | Principal | Interest | End Balance |
|---|---|---|---|---|
| 1 | $18,962.04 | $2,794.31 | $16,167.73 | $247,205.69 |
| 2 | $18,962.04 | $2,981.45 | $15,980.59 | $244,224.23 |
| 3 | $18,962.04 | $3,181.13 | $15,780.91 | $241,043.10 |
| 4 | $18,962.04 | $3,394.17 | $15,567.87 | $237,648.93 |
| 5 | $18,962.04 | $3,621.49 | $15,340.55 | $234,027.44 |
| 6 | $18,962.04 | $3,864.03 | $15,098.02 | $230,163.42 |
| 7 | $18,962.04 | $4,122.81 | $14,839.23 | $226,040.61 |
| 8 | $18,962.04 | $4,398.92 | $14,563.12 | $221,641.69 |
| 9 | $18,962.04 | $4,693.52 | $14,268.52 | $216,948.17 |
| 10 | $18,962.04 | $5,007.86 | $13,954.18 | $211,940.32 |
| 11 | $18,962.04 | $5,343.24 | $13,618.80 | $206,597.07 |
| 12 | $18,962.04 | $5,701.09 | $13,260.95 | $200,895.99 |
Formula
How to use this calculator
- Enter the loan amount. For a mortgage, this is purchase price minus down payment, not the home price.
- Enter the annual interest rate (the note rate). For mortgages, don't use APR — APR is for comparing offers, the note rate drives the math.
- Enter the loan term in years.
- Review the schedule. Use the yearly summary view to see how much principal and interest you'll pay each year — useful for tax planning, since mortgage interest is deductible up to current IRS limits.
- Compare the schedule for different rates and terms. A 15-year loan front-loads principal much faster than a 30-year — total interest can be cut by 60% or more.
Worked examples
15-year vs 30-year
$300,000 loan at 6.5%: 30-year: payment $1,896, total interest $382,633 15-year: payment $2,613, total interest $170,290 The 15-year saves $212,343 in lifetime interest. After 5 years on each loan: 30-year balance: $279,900 (only $20K principal paid) 15-year balance: $237,400 (about $63K principal paid) The 15-year builds equity 3× faster.
Extra principal payment
$250,000 at 6.5% for 30 years. Pay an extra $200/month from month 1. Without extras: 360 months, $318,861 interest With $200 extra: ≈ 308 months, $264,000 interest Just $200/month extra pays off the loan 4 years and 4 months early and saves ≈ $55,000. Extra payments early have the largest impact.
When to use this calculator
Use this calculator to understand exactly how a loan gets paid off — useful when comparing loan terms, planning extra principal payments, or evaluating whether to refinance. The schedule is also useful for tax planning: mortgage interest is deductible (subject to limits), and the schedule tells you how much you'll pay each year.
For loans with non-standard features — interest-only periods, balloon payments, adjustable rates, variable principal — this calculator won't capture them. Use the specific calculators for ARM loans, balloon mortgages, or interest-only loans instead. For accelerated payoff strategies across multiple debts, use the debt snowball or accelerated payoff calculators.
Common mistakes to avoid
- Confusing payment amount with cost. The monthly payment is constant on a fixed-rate loan; the interest paid each month declines while principal grows.
- Thinking "halfway through the loan" means half the principal is paid off. On a 30-year mortgage, you typically pay off half the principal somewhere between years 20 and 22.
- Underestimating extra-payment impact. A few hundred dollars extra applied to principal in the first few years can save tens of thousands over the loan.
- Comparing only monthly payments when shopping loan terms. Total interest tells the truer story.
- Forgetting that interest is calculated on the current balance, not the original. Pay down principal, and future interest charges shrink.
Frequently Asked Questions
Sources & further reading
- Understanding mortgage amortization — U.S. Consumer Financial Protection Bureau
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