Amortization Schedule Calculator
Build a full month-by-month amortization schedule from your loan amount, rate and term. See principal, interest and balance for every payment, with CSV export.
Schedule — 360 payments
| Period | Paid | Interest | Principal | Balance |
|---|---|---|---|---|
| $14,389.20 | $11,933.19 | $2,456.01 | $197,543.99 | |
| Payment 1 | $1,199.10 | $1,000.00 | $199.10 | $199,800.90 |
| Payment 2 | $1,199.10 | $999.00 | $200.10 | $199,600.80 |
| Payment 3 | $1,199.10 | $998.00 | $201.10 | $199,399.70 |
| Payment 4 | $1,199.10 | $997.00 | $202.10 | $199,197.60 |
| Payment 5 | $1,199.10 | $995.99 | $203.11 | $198,994.49 |
| Payment 6 | $1,199.10 | $994.97 | $204.13 | $198,790.36 |
| Payment 7 | $1,199.10 | $993.95 | $205.15 | $198,585.21 |
| Payment 8 | $1,199.10 | $992.93 | $206.17 | $198,379.04 |
| Payment 9 | $1,199.10 | $991.90 | $207.20 | $198,171.84 |
| Payment 10 | $1,199.10 | $990.86 | $208.24 | $197,963.60 |
| Payment 11 | $1,199.10 | $989.82 | $209.28 | $197,754.32 |
| Payment 12 | $1,199.10 | $988.77 | $210.33 | $197,543.99 |
| $14,389.20 | $11,781.71 | $2,607.49 | $194,936.50 | |
| $14,389.20 | $11,620.90 | $2,768.30 | $192,168.20 | |
| $14,389.20 | $11,450.13 | $2,939.07 | $189,229.13 | |
| $14,389.20 | $11,268.87 | $3,120.33 | $186,108.80 | |
| $14,389.20 | $11,076.40 | $3,312.80 | $182,796.00 | |
| $14,389.20 | $10,872.07 | $3,517.13 | $179,278.87 | |
| $14,389.20 | $10,655.14 | $3,734.06 | $175,544.81 | |
| $14,389.20 | $10,424.85 | $3,964.35 | $171,580.46 | |
| $14,389.20 | $10,180.34 | $4,208.86 | $167,371.60 | |
| $14,389.20 | $9,920.75 | $4,468.45 | $162,903.15 | |
| $14,389.20 | $9,645.14 | $4,744.06 | $158,159.09 | |
| $14,389.20 | $9,352.53 | $5,036.67 | $153,122.42 | |
| $14,389.20 | $9,041.89 | $5,347.31 | $147,775.11 | |
| $14,389.20 | $8,712.07 | $5,677.13 | $142,097.98 | |
| $14,389.20 | $8,361.91 | $6,027.29 | $136,070.69 | |
| $14,389.20 | $7,990.16 | $6,399.04 | $129,671.65 | |
| $14,389.20 | $7,595.49 | $6,793.71 | $122,877.94 | |
| $14,389.20 | $7,176.50 | $7,212.70 | $115,665.24 | |
| $14,389.20 | $6,731.62 | $7,657.58 | $108,007.66 | |
| $14,389.20 | $6,259.30 | $8,129.90 | $99,877.76 | |
| $14,389.20 | $5,757.87 | $8,631.33 | $91,246.43 | |
| $14,389.20 | $5,225.50 | $9,163.70 | $82,082.73 | |
| $14,389.20 | $4,660.31 | $9,728.89 | $72,353.84 | |
| $14,389.20 | $4,060.26 | $10,328.94 | $62,024.90 | |
| $14,389.20 | $3,423.18 | $10,966.02 | $51,058.88 | |
| $14,389.20 | $2,746.82 | $11,642.38 | $39,416.50 | |
| $14,389.20 | $2,028.74 | $12,360.46 | $27,056.04 | |
| $14,389.20 | $1,266.39 | $13,122.81 | $13,933.23 | |
| $14,390.24 | $457.01 | $13,933.23 | $0.00 |
Assumes a fixed rate and equal monthly payments, with the last instalment adjusted so the balance ends at exactly zero. Taxes, insurance and fees are excluded. Estimates only, not financial advice.
What is the Amortization Schedule Calculator?
The ByteTools Amortization Schedule Calculator turns a loan amount, an annual interest rate and a term into the complete payment table your lender works from.
- Full month-by-month principal, interest and balance breakdown
- Grouped by year and collapsible, so a 30-year schedule stays readable on any screen
- Optional start month that turns payment numbers into real dates
- Optional extra monthly payment showing the interest and time it saves
- Final payment absorbs rounding so the balance lands on exactly zero
- One-click CSV download of the complete schedule
- Runs offline in your browser; no data leaves the page
How to use the Amortization Schedule Calculator
- 1
Enter the loan amount, the annual interest rate and the term in years.
- 2
Optionally set the first payment month so the schedule shows real dates.
- 3
Add an extra monthly payment to see how much interest and time it saves.
- 4
Read the monthly payment, total interest and total of payments at the top.
- 5
Expand any year in the schedule to see its individual payments.
- 6
Download the whole schedule as CSV to open in a spreadsheet.
About the Amortization Schedule Calculator
The ByteTools Amortization Schedule Calculator turns a loan amount, an annual interest rate and a term into the complete payment table your lender works from. It uses the standard annuity payment formula to find the level monthly payment, then walks the balance forward month by month so you can see exactly how much of each payment goes to interest and how much reduces the principal.
It is built for mortgage holders, car buyers and small-business borrowers who want to see the real shape of a loan rather than a single monthly figure. The schedule is grouped a year at a time so it stays readable on a phone, and the whole thing downloads as a CSV file you can open in Excel, Numbers or Google Sheets.
Everything is calculated locally in your browser — your loan figures are never uploaded, stored or sent anywhere. Results are estimates for planning only and are not financial advice; your lender's schedule may differ slightly because of day-count conventions and fees.
Frequently asked questions
What is an amortization schedule?
An amortization schedule is a table showing every payment on a loan, split into the interest charged that month and the principal that actually reduces your debt. Early payments are mostly interest; later payments are mostly principal, because interest is charged on a shrinking balance.
How is the monthly payment calculated?
It uses the standard annuity formula: payment = L × i ÷ (1 − (1 + i)^−n), where L is the loan amount, i is the monthly rate (annual rate ÷ 12) and n is the number of payments. A $200,000 loan at 6% over 30 years gives $1,199.10 a month.
Why does the last payment differ from the others?
Payments are rounded to whole cents, so tiny rounding differences build up over hundreds of months. The final payment absorbs whatever residual is left, which is why it is usually a few cents larger or smaller and leaves the balance at exactly zero.
How much interest will I pay in total?
Total interest is the sum of the interest column across the whole schedule — the total of all payments minus the amount you borrowed. On a $250,000 loan at 6.5% over 30 years it comes to about $318,900, more than the loan itself.
Why is so much of an early payment interest?
Interest is charged on the balance you still owe, and early on that balance is almost the full loan. As the principal column grows each month the interest column shrinks, which is why the split flips roughly two-thirds of the way through a long loan.
Is my loan information private?
Completely. The whole schedule is generated by JavaScript inside your browser, so nothing you type is uploaded or saved on a server.
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