Real Interest Calculator
Find the true annual interest rate implied by lease amount, term, and monthly instalment — compare to advertised rates
Lease details
Lease amount
Principal being financed (after any down payment)
Lease period
4 years · up to 7 years
Monthly instalment
Exact recurring payment in your quotation
Real annual interest rate (nominal)
12.00%
Quoted like vehicle loans: monthly rests, annual rate ÷ 12 per month
Effective annual rate
12.68%
APR-style (monthly compounding)
Total amount paid
Rs. 3,033,600.00
48 × instalment
Total interest paid
Rs. 633,600.00
Over full term
Lease principal share
79.1%
Of total paid
Breakdown
Enter the financed lease amount, contract length, and the monthly instalment you were quoted. We solve for the real annual rate implied by those numbers (reducing balance, same maths as our vehicle loan and lease calculators).
Finance providers sometimes quote simple or flat rates that look lower than the equivalent reducing-balance rate. Enter the financed amount, how many months you pay, and the instalment on your offer: we solve for the nominal annual rate that matches standard amortisation (the same basis as our vehicle loan and lease calculators), plus total interest and total paid.
Frequently asked questions
- What interest rate does this show?
- The nominal annual rate with monthly rests (annual rate divided by 12 each month), matching typical vehicle loan and lease calculators in Sri Lanka. We also show an effective annual rate so you can compare to simple or flat-rate marketing.
- Why is it different from what the salesperson said?
- Advertised figures may use flat interest, add-ons, or rounding. This tool only uses principal, term, and instalment to reverse‑engineer the rate implied by standard reducing‑balance maths.
- Does this include fees or insurance?
- No. If fees are bundled into the financed amount, include that in the lease amount. If they are separate cash payments, add them mentally to the total cost of the deal.