Free lending tool
Amortization schedule generator
Every instalment, with the date it falls due and exactly how much of it is interest, how much clears the debt, and what is left afterwards. Enter the loan terms below, then download the schedule as a spreadsheet or a PDF.
Loan terms
The annuity method behind most bank loans and mortgages. Interest is charged on the balance still owed, and the instalment stays the same — the split simply shifts from interest to principal.
Optional. Add one to put a real due date on every instalment. Month-end dates are kept — a schedule starting on the 31st falls on the 28th in February and the 31st again in March.
Optional. Service, admin or insurance charges added to every repayment.
Monthly instalment
ZAR 12,481.03
24 payments, ZAR 49,544.61 of interest over the life of the loan.
- Loan amount
- ZAR 250,000.00
- Scheduled instalment
- ZAR 12,481.03
- Number of payments
- 24
- Total interest
- ZAR 49,544.61
- Total repaid
- ZAR 299,544.61
An estimate for planning. Your own rounding rules, day-count convention and payment dates may shift individual instalments by a small amount.
The full schedule
Every instalment, in order. The final payment absorbs any rounding so the balance lands exactly on zero.
| # | Opening balance | Payment | Interest | Principal | Closing balance |
|---|---|---|---|---|---|
| 1 | ZAR 250,000.00 | ZAR 12,481.03 | ZAR 3,750.00 | ZAR 8,731.03 | ZAR 241,268.97 |
| 2 | ZAR 241,268.97 | ZAR 12,481.03 | ZAR 3,619.03 | ZAR 8,861.99 | ZAR 232,406.98 |
| 3 | ZAR 232,406.98 | ZAR 12,481.03 | ZAR 3,486.10 | ZAR 8,994.92 | ZAR 223,412.06 |
| 4 | ZAR 223,412.06 | ZAR 12,481.03 | ZAR 3,351.18 | ZAR 9,129.84 | ZAR 214,282.22 |
| 5 | ZAR 214,282.22 | ZAR 12,481.03 | ZAR 3,214.23 | ZAR 9,266.79 | ZAR 205,015.43 |
| 6 | ZAR 205,015.43 | ZAR 12,481.03 | ZAR 3,075.23 | ZAR 9,405.79 | ZAR 195,609.63 |
| 7 | ZAR 195,609.63 | ZAR 12,481.03 | ZAR 2,934.14 | ZAR 9,546.88 | ZAR 186,062.75 |
| 8 | ZAR 186,062.75 | ZAR 12,481.03 | ZAR 2,790.94 | ZAR 9,690.08 | ZAR 176,372.67 |
| 9 | ZAR 176,372.67 | ZAR 12,481.03 | ZAR 2,645.59 | ZAR 9,835.44 | ZAR 166,537.23 |
| 10 | ZAR 166,537.23 | ZAR 12,481.03 | ZAR 2,498.06 | ZAR 9,982.97 | ZAR 156,554.26 |
| 11 | ZAR 156,554.26 | ZAR 12,481.03 | ZAR 2,348.31 | ZAR 10,132.71 | ZAR 146,421.55 |
| 12 | ZAR 146,421.55 | ZAR 12,481.03 | ZAR 2,196.32 | ZAR 10,284.70 | ZAR 136,136.85 |
What an amortization schedule tells you
The instalment is one number. The schedule is what that number is actually doing, month after month.
- 1
The split moves over time
On a reducing-balance loan the early instalments are mostly interest and the later ones mostly principal, even though the payment never changes. That is why paying off a loan in its first months barely dents the balance.
- 2
It shows what settlement costs
The closing balance on any row is what the borrower would owe if they settled after that payment. Without the schedule, an early-settlement quote is guesswork — and a common source of disputes.
- 3
It is the record you both work from
A dated schedule handed over at disbursement tells the borrower exactly what falls due and when, and gives your collections team the same figures. Most arrears arguments start with two parties reading different numbers.
The four ways a loan is amortized
Two questions decide the shape of a schedule: how interest is charged, and how the principal is retired. The combinations lenders actually use come down to these four.
| Method | Instalment | How it works |
|---|---|---|
| Reducing balance, equal instalments | Level | The annuity or EMI method. Interest accrues on what is still outstanding, and the payment is solved so that the loan clears exactly on the final instalment. Early payments are mostly interest, later ones mostly principal. |
| Reducing balance, equal principal | Declining | Also called straight-line or constant amortization. The same slice of principal comes back every period and interest is charged on the falling balance, so the first instalment is the largest. It costs the borrower less overall than equal instalments at the same rate. |
| Flat rate | Level | Interest is calculated once on the original amount for the whole term, then divided evenly across the instalments. The balance shrinking is ignored, which is why a flat rate’s effective cost is roughly double its headline number. |
| Interest-only with balloon | Interest, then a lump sum | Only interest is paid until maturity, when the whole principal falls due at once. Because nothing is repaid along the way, this carries the most interest of the four — and the repayment risk sits entirely on the final date. |
Two related ideas sit outside this list. A partial balloon amortizes on a longer notional term and settles the remainder in a lump sum. The Rule of 78s is not a schedule at all but a way of allocating flat-rate interest for early-settlement rebates, and it is restricted or banned in a number of markets.
Reading the schedule
What each column means, and why it is there.
- Opening balance
- What is still owed before this instalment is paid. On the first row it is the full loan amount; on the last it is the amount the final payment clears.
- Payment
- The instalment due. Under the two level-payment methods it is identical on every row except the last, which is adjusted by a few cents so the schedule finishes exactly at zero. Under equal principal it declines each period, and under interest-only it stays small until the balloon.
- Interest
- The charge for this period. Under any reducing-balance method it falls as the debt does. Under a flat rate it is the same on every row, because the charge was calculated on the original amount at the outset. Interest-only holds it constant too, since the balance never moves.
- Principal
- The part of the payment that actually reduces the debt. It grows over the life of an equal-instalment loan, stays constant under equal principal, and is zero until the final balloon under interest-only.
- Closing balance
- What remains after the payment. It is the settlement figure at that point in the loan, and it must reach exactly zero on the final row.
Add a per-instalment fee and it appears as its own column, kept separate from interest — because it is a charge for a service, not a price for the money, and most regulators expect it disclosed that way.
Questions about amortization schedules
- No. Flat and reducing balance describe how interest is charged, which is only half the picture — the other half is how the principal is repaid. A reducing-balance loan can be repaid in equal instalments (the annuity or EMI method) or in equal principal slices, which produces a declining payment and a lower total cost. Add interest-only with a balloon at maturity and you have the four structures covered by this tool.
- Both charge interest on the outstanding balance, so both are reducing-balance loans. Equal instalments keep the payment identical throughout and vary the split inside it. Equal principal keeps the principal portion identical and lets the payment fall as interest declines. Equal principal costs the borrower less in total, because the debt is retired faster in the early periods — but it demands more cash up front, which is why consumer lenders tend to prefer equal instalments.
- Where the borrower expects a single future event to repay the capital — a property sale, a harvest, an invoice settlement, a refinance. It keeps periodic outgoings low, but nothing is repaid along the way, so it carries the most interest of the four structures and concentrates the entire repayment risk on one date. Most lenders pair it with a clear exit plan and security.
- A table showing every instalment on a loan, and for each one how much goes to interest, how much reduces the principal, and what balance is left afterwards. It turns a single monthly figure into the full picture of how a debt is repaid.
- Because interest is charged on what is outstanding, and at the start almost the whole loan is outstanding. As the balance falls the interest portion shrinks and the principal portion grows, even though the instalment itself never changes. This only applies to reducing-balance loans; under a flat rate the split stays constant.
- Yes — switch the interest method above. The schedule will show the same interest on every row, since a flat rate charges on the original amount throughout. If you want to see what that costs against a reducing balance, use the flat vs reducing balance comparator.
- Rounding. Each instalment is rounded to the currency’s smallest unit, and over dozens of payments those fractions accumulate. The final payment absorbs the difference so the balance lands exactly on zero — which is what almost every lender does in practice.
- Each date is measured from the first payment date rather than from the previous instalment, so the schedule cannot drift. Month-end dates are preserved: a schedule starting on 31 January falls due on 28 February, then 31 March, rather than moving to the 28th for the rest of the year.
- Yes. CSV opens in Excel, Google Sheets or any spreadsheet, with plain unformatted numbers so nothing has to be cleaned up first. The PDF is real, selectable text rather than an image, so figures can be copied out of it.
- No. The whole calculation runs in your browser, and the exports are generated on your own device. Nothing you type is sent to a server, saved, or logged, and there is no sign-up.
Is amortization only flat or reducing balance?
What is the difference between equal instalments and equal principal?
When should I use an interest-only balloon?
What is an amortization schedule?
Why is so much of my early payment interest?
Can I generate a schedule for a flat-rate loan?
Why doesn’t the last payment match the others?
How are due dates calculated?
Can I export the schedule?
Is my data stored?
Stop rebuilding schedules by hand
Lendbox generates the schedule at disbursement, tracks every payment against it, flags arrears the day they occur and recalculates automatically when a loan is restructured or settled early.
No credit card required.
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