Loan Amortization Calculator
Your payment, the total interest, and every single payment split into interest and principal — plus a live Excel schedule you can poke at.
Ben / Reviewed Sep 27, 2026 / v2.0.0
Results
Showing the numbers you calculated- Payment
- $1,580.17
- Principal + interest only
- Total interest
- $318,861.58
- Total of all payments
- $568,861.58
- Number of payments
- 360
- First payment
- 09/01/2026
- Payoff date
- 08/01/2056
- Date of the last payment
- Current portion at start
- $2,794.31
- Principal due in the first 12 months
- Long-term portion at start
- $247,205.69
Amortization schedule
Swipe the table sideways to see all 6 columns.
| # | Date | Payment | Interest | Principal | Balance |
|---|---|---|---|---|---|
| 1 | 09/01/2026 | $1,580.17 | $1,354.17 | $226.00 | $249,774.00 |
| 2 | 10/01/2026 | $1,580.17 | $1,352.94 | $227.23 | $249,546.77 |
| 3 | 11/01/2026 | $1,580.17 | $1,351.71 | $228.46 | $249,318.31 |
| 4 | 12/01/2026 | $1,580.17 | $1,350.47 | $229.70 | $249,088.61 |
| 5 | 01/01/2027 | $1,580.17 | $1,349.23 | $230.94 | $248,857.67 |
| 6 | 02/01/2027 | $1,580.17 | $1,347.98 | $232.19 | $248,625.48 |
| 7 | 03/01/2027 | $1,580.17 | $1,346.72 | $233.45 | $248,392.03 |
| 8 | 04/01/2027 | $1,580.17 | $1,345.46 | $234.71 | $248,157.32 |
| 9 | 05/01/2027 | $1,580.17 | $1,344.19 | $235.98 | $247,921.34 |
| 10 | 06/01/2027 | $1,580.17 | $1,342.91 | $237.26 | $247,684.08 |
| 11 | 07/01/2027 | $1,580.17 | $1,341.62 | $238.55 | $247,445.53 |
| 12 | 08/01/2027 | $1,580.17 | $1,340.33 | $239.84 | $247,205.69 |
| 13 | 09/01/2027 | $1,580.17 | $1,339.03 | $241.14 | $246,964.55 |
| 14 | 10/01/2027 | $1,580.17 | $1,337.72 | $242.45 | $246,722.10 |
| 15 | 11/01/2027 | $1,580.17 | $1,336.41 | $243.76 | $246,478.34 |
| 16 | 12/01/2027 | $1,580.17 | $1,335.09 | $245.08 | $246,233.26 |
| 17 | 01/01/2028 | $1,580.17 | $1,333.76 | $246.41 | $245,986.85 |
| 18 | 02/01/2028 | $1,580.17 | $1,332.43 | $247.74 | $245,739.11 |
| 19 | 03/01/2028 | $1,580.17 | $1,331.09 | $249.08 | $245,490.03 |
| 20 | 04/01/2028 | $1,580.17 | $1,329.74 | $250.43 | $245,239.60 |
| 21 | 05/01/2028 | $1,580.17 | $1,328.38 | $251.79 | $244,987.81 |
| 22 | 06/01/2028 | $1,580.17 | $1,327.02 | $253.15 | $244,734.66 |
| 23 | 07/01/2028 | $1,580.17 | $1,325.65 | $254.52 | $244,480.14 |
| 24 | 08/01/2028 | $1,580.17 | $1,324.27 | $255.90 | $244,224.24 |
Annual summary
Swipe the table sideways to see all 5 columns.
| Year | Payments | Interest | Principal | Year-end balance |
|---|---|---|---|---|
| 2026 | $6,320.68 | $5,409.29 | $911.39 | $249,088.61 |
| 2027 | $18,962.04 | $16,106.69 | $2,855.35 | $246,233.26 |
| 2028 | $18,962.04 | $15,915.48 | $3,046.56 | $243,186.70 |
| 2029 | $18,962.04 | $15,711.44 | $3,250.60 | $239,936.10 |
| 2030 | $18,962.04 | $15,493.72 | $3,468.32 | $236,467.78 |
| 2031 | $18,962.04 | $15,261.46 | $3,700.58 | $232,767.20 |
| 2032 | $18,962.04 | $15,013.61 | $3,948.43 | $228,818.77 |
| 2033 | $18,962.04 | $14,749.18 | $4,212.86 | $224,605.91 |
| 2034 | $18,962.04 | $14,467.05 | $4,494.99 | $220,110.92 |
| 2035 | $18,962.04 | $14,166.01 | $4,796.03 | $215,314.89 |
| 2036 | $18,962.04 | $13,844.81 | $5,117.23 | $210,197.66 |
| 2037 | $18,962.04 | $13,502.08 | $5,459.96 | $204,737.70 |
| 2038 | $18,962.04 | $13,136.43 | $5,825.61 | $198,912.09 |
| 2039 | $18,962.04 | $12,746.29 | $6,215.75 | $192,696.34 |
| 2040 | $18,962.04 | $12,330.01 | $6,632.03 | $186,064.31 |
| 2041 | $18,962.04 | $11,885.84 | $7,076.20 | $178,988.11 |
| 2042 | $18,962.04 | $11,411.93 | $7,550.11 | $171,438.00 |
| 2043 | $18,962.04 | $10,906.27 | $8,055.77 | $163,382.23 |
| 2044 | $18,962.04 | $10,366.79 | $8,595.25 | $154,786.98 |
| 2045 | $18,962.04 | $9,791.13 | $9,170.91 | $145,616.07 |
| 2046 | $18,962.04 | $9,176.95 | $9,785.09 | $135,830.98 |
| 2047 | $18,962.04 | $8,521.61 | $10,440.43 | $125,390.55 |
| 2048 | $18,962.04 | $7,822.41 | $11,139.63 | $114,250.92 |
| 2049 | $18,962.04 | $7,076.35 | $11,885.69 | $102,365.23 |
| 2050 | $18,962.04 | $6,280.36 | $12,681.68 | $89,683.55 |
| 2051 | $18,962.04 | $5,431.03 | $13,531.01 | $76,152.54 |
| 2052 | $18,962.04 | $4,524.84 | $14,437.20 | $61,715.34 |
| 2053 | $18,962.04 | $3,557.96 | $15,404.08 | $46,311.26 |
| 2054 | $18,962.04 | $2,526.31 | $16,435.73 | $29,875.53 |
| 2055 | $18,962.04 | $1,425.58 | $17,536.46 | $12,339.07 |
| 2056 | $12,641.74 | $302.67 | $12,339.07 | $0.00 |
Suggested journal entries
Suggested entries for your records — adjust account names to your chart of accounts.
| Account | Debit | Credit |
|---|---|---|
| 08/01/2026 — Record the loan | ||
| Cash | $250,000.00 | |
| Notes payable | $250,000.00 | |
| Totals | $250,000.00 | $250,000.00 |
| 09/01/2026 — Payment #1 (every payment follows the schedule's interest/principal split) | ||
| Interest expense | $1,354.17 | |
| Notes payable | $226.00 | |
| Cash | $1,580.17 | |
| Totals | $1,580.17 | $1,580.17 |
What this does
Give it a loan amount, rate, and term, and it builds the whole amortization schedule: what each payment is, how much of it is interest, how much actually knocks down the balance, and when you're done.
The download is a real spreadsheet, not a screenshot — the payment is a PMT() formula, every row of the schedule is a formula, and if you change the rate or term in Excel the whole thing re-runs.
How the math works
The payment is the standard level-payment formula (Excel's PMT):
Payment = P × r ÷ (1 − (1 + r)^−n)
- P = loan amount
- r = interest rate per payment (annual rate ÷ payments per year)
- n = number of payments (years × payments per year)
Then every row does the same three steps: interest = balance × r (rounded to the cent), principal = payment − interest, new balance = old balance − principal.
Because the payment and each interest charge are rounded to cents — exactly how lenders do it — the last payment is usually off by a few cents. It absorbs the leftover so the balance ends at $0.00, and the schedule always adds up: total principal equals the loan amount.
Early payments are mostly interest because interest is charged on the balance, and the balance is biggest at the start. That's not a trick; it's just math that feels like one.
Check my math: a worked example
Say you borrow $250,000 at 6.50% for 30 years, paid monthly, starting 08/01/2026.
- Rate per payment: 6.50% ÷ 12 = 0.5417%.
- Number of payments: 30 × 12 = 360.
- Payment: $1,580.17 (first one due 09/01/2026).
- Payment #1 splits into $1,354.17 of interest and $226.00 of principal.
- Over the life of the loan you pay $568,861.58 in total — $318,861.58 of that is interest.
- The last payment lands on 08/01/2056.
If this loan showed up on a balance sheet the day it was signed, $2,794.31 would be the current portion (principal due in the first year) and $247,205.69 would be long-term.
These numbers come straight from the calculator using its example inputs — if the math ever changes, this example changes with it.
Mistakes I see a lot
- Typing the rate as a decimal. 6.5% goes in as 6.5, not 0.065.
- Assuming the "start date" is the first payment. Loans usually start one period before the first payment is due — enter a first payment date if yours is different.
- Comparing your lender's payment to this one when yours includes escrow. Taxes, insurance, and PMI aren't principal or interest.
- Thinking a 26-payment "every two weeks" loan is the same as paying half your monthly payment every two weeks. The second one sneaks in an extra monthly payment each year — use the Extra Payment calculator to model it.
Questions people ask
- Why is my last payment different from the others?
- Rounding. The payment and each month's interest are rounded to the cent, so after hundreds of payments a few cents are left over. The final payment picks them up so the balance ends at exactly $0.
- Will this match my lender's schedule to the penny?
- Usually very close. Differences come from how the lender counts days (some use actual days in the month), when your first payment is due, and whether they charge odd-days interest at closing.
- Does the Excel file actually recalculate?
- Yes. The yellow cells on the Inputs sheet are yours to change. The payment, the full schedule, the annual totals, and the journal entries are all formulas — change the rate and everything updates.
- What's the "current portion" thing?
- It's for bookkeeping. On a balance sheet, the principal you'll pay in the next 12 months is a current liability and the rest is long-term. The calculator shows that split as of the loan's start date.
- Can I see what extra payments would do?
- That's the Extra Payment calculator — same schedule, plus recurring or one-time extra principal, and how much interest and time it saves.
Assumptions and limits
- Fixed interest rate for the whole term; payments are made at the end of each period.
- The payment is rounded to the cent and each period's interest is rounded to the cent — the way lenders do it. The final payment absorbs the leftover pennies so the balance lands on exactly $0.
- Interest per period = annual rate ÷ payments per year (a 12-payments-per-year loan charges 1/12 of the annual rate each month, regardless of days in the month).
- If you don't enter a first payment date, the first payment is one period after the loan start date. A first payment date doesn't change the interest in period 1 (no odd-days interest).
- Every-two-weeks and weekly schedules are true 26- and 52-payment-per-year loans, not a monthly loan paid in halves.
- No escrow (taxes, insurance, PMI), fees, prepayment penalties, or rate changes.
- "Current portion" is the principal due in the first 12 months of payments — the part that's classified as a current liability on a balance sheet dated at the start of the loan.
Disclaimer: Educational and planning use only. Results depend on what you enter and may not match your lender, your tax return, or professional accounting treatment. Informational content + opinions only — not tax/legal advice.