Loan schedule calculator
Price a loan flat and on a declining balance, weekly, fortnightly or monthly, and see every instalment. It runs the same schedule engine as the Fused product.
- Total interest, flat
- LKR 24,000.00
- Total interest, declining balance
- LKR 13,471.53
- Flat costs the borrower more by
- LKR 10,528.47
12 instalments, maturing 1 Oct 2027. Amounts in LKR.
| No. | Due date | Principal | Interest | Instalment | Balance after |
|---|---|---|---|---|---|
| 1 | 1 Nov 2026 | 7,455.96 | 2,000.00 | 9,455.96 | 92,544.04 |
| 2 | 1 Dec 2026 | 7,605.08 | 1,850.88 | 9,455.96 | 84,938.96 |
| 3 | 1 Jan 2027 | 7,757.18 | 1,698.78 | 9,455.96 | 77,181.78 |
| 4 | 1 Feb 2027 | 7,912.32 | 1,543.64 | 9,455.96 | 69,269.46 |
| 5 | 1 Mar 2027 | 8,070.57 | 1,385.39 | 9,455.96 | 61,198.89 |
| 6 | 1 Apr 2027 | 8,231.98 | 1,223.98 | 9,455.96 | 52,966.91 |
| 7 | 1 May 2027 | 8,396.62 | 1,059.34 | 9,455.96 | 44,570.29 |
| 8 | 1 Jun 2027 | 8,564.55 | 891.41 | 9,455.96 | 36,005.74 |
| 9 | 1 Jul 2027 | 8,735.85 | 720.11 | 9,455.96 | 27,269.89 |
| 10 | 1 Aug 2027 | 8,910.56 | 545.40 | 9,455.96 | 18,359.33 |
| 11 | 1 Sep 2027 | 9,088.77 | 367.19 | 9,455.96 | 9,270.56 |
| 12 | 1 Oct 2027 | 9,270.56 | 185.41 | 9,455.97 | 0.00 |
| Total | 100,000.00 | 13,471.53 | 113,471.53 | ||
Each period is an equal share of the year and interest is rounded half up. A Fused loan product sets these per product, along with the day count, grace periods and holiday rescheduling.
Reading the schedule
On a flat loan the interest is fixed at the start: principal, times the yearly rate, times the term in years, spread evenly across the instalments. On a declining balance each instalment’s interest is the periodic rate on what is still owed, which is why the interest column falls as the balance does.
The comparison above uses equal instalments for both methods, so the only difference is how interest is worked out. For the full arithmetic with a worked example, readFlat rate vs reducing balance: the same loan, two prices.
About the calculator
What is the difference between a flat rate and a reducing balance?
A flat rate charges interest on the original principal for the whole term. A reducing (declining) balance charges each period’s interest only on the principal still outstanding, so the same headline rate costs the borrower less.
How is the instalment on a declining balance worked out?
With equal instalments, the instalment is the annuity that repays the principal over the term at the periodic rate. The split between principal and interest then changes every period: early instalments are mostly interest, later ones mostly principal.
Why does the last instalment differ by a few cents?
Each instalment is rounded, so a small difference is left over. The schedule puts it on the last instalment, or the first if you choose, so the schedule repays exactly the principal disbursed.
Is this the same arithmetic Fused uses?
Yes. The calculator runs a copy of the Fused schedule engine, and the copy is tested against the product’s own worked examples on every build.
Your products, priced by the same engine.
A walkthrough with the team that builds Fused: your loan products, your branches, your month-end.