Sri Lanka Vehicle Leasing Calculator

A vehicle finance lease in Sri Lanka is a regulated product under the Finance Leasing Act No. 56 of 2000. The lessor (a licensed finance company — People's Leasing, LB Finance, Commercial Leasing, LOLC, Singer Finance, Vallibel, and similar) holds the absolute title to the vehicle for the term; you pay an up-front advance plus a fixed monthly rental for an agreed number of months; ownership transfers to you with the final rental. The maths under the rental is the standard level-payment annuity, and the Central Bank caps the rate at 18% AER per Monetary Board Direction No. 1 of 2023.

The calculator follows five steps, each of which the page exposes so you can audit the working by hand:

1. Compute the financed principal: P = vehicle price − advance. The documentation fee is treated as an up-front cash cost, not financed, because that is how every licensed finance company actually structures the schedule.
2. Convert the quoted annual rate to a monthly periodic rate: r = annual ÷ 12. The calculator treats the input as a nominal annual rate compounded monthly (the convention in CBSL Direction No. 1 of 2023 §3) and also shows the implied effective annual rate EAR = (1 + r)^12 − 1, so the user sees both numbers side by side.
3. Solve for the level monthly rental using the annuity formula with an end-of-term residual: Rental = [P − RV × (1+r)^(−n)] × r / (1 − (1+r)^(−n)). With residual RV = 0 this collapses to the textbook EMI formula. With RV > 0 it correctly amortises only the non-residual portion of the principal so the closing balance at month n equals the residual to the rupee.
4. Build the amortisation schedule month by month. For each row: interest portion = opening balance × r; principal portion = rental − interest portion; closing balance = opening balance − principal portion. The final row's closing balance is forced to equal the residual to absorb the tiny rounding drift that the closed-form formula accumulates over the term — never more than a few cents.
5. Sum the totals and check the ceiling: total of rentals = rental × n; total interest = total of rentals + residual − P; total cash out = advance + total of rentals + residual + documentation fee. If the entered annual rate exceeds 18% the page renders an amber disclosure citing the CBSL direction; otherwise a green badge confirms compliance.

Why a quoted "flat rate" can mislead

Sri Lankan dealers sometimes quote a flat-rate version of the same lease — interest charged on the full principal for the full term, divided across the months. A 10% flat rate over 60 months on a Rs 4,000,000 principal works out to a monthly rental of about Rs 100,000, which looks competitive on the showroom floor. But because the rental is constant while the outstanding balance falls, the true effective AER is closer to 18% — at or above the CBSL ceiling. The calculator always treats your input as a reducing-balance AER, which is the disclosure convention the CBSL direction requires. If you have only a flat rate to work with, multiply by roughly 1.8 to get the equivalent AER on a 5-year term, then enter that into the rate field — the resulting monthly rental should match the dealer's quote to within a few hundred rupees.

What this calculator does not include

Bundled insurance is shown as an opt-in disclosure rather than a line of math, because comprehensive premiums for the same vehicle vary by 20–40% across insurers and depend on the no-claims bonus history of the registered keeper. Get a written premium quote from the lessor's preferred insurer (or your own broker) and add the monthly figure on top of the rental shown here. The page also stays out of vehicle-import duty and revenue licence territory — those use the revenue licence calculator and the customs HS-code finder. Hire purchase agreements are legally distinct under Hire Purchase Act No. 7 of 1959; this tool handles finance leases only.

Cross-checks the calculator performs for you

Three independent checks run on every input change. (1) The closed-form rental is reconciled against the amortisation walk — the period-by-period sum of interest portions equals the closed-form total interest to within a rupee. (2) A bisection solver recovers the input annual rate from the computed rental and term, confirming the annuity equation is invertible at the rate we used. (3) The final closing balance is forced to equal the residual you entered, exposing any drift from floating-point accumulation; a healthy schedule never drifts more than a few cents before the correction. If any check fails, the result panel shows an error rather than a misleading number.

Three scenarios that map to the most common Sri Lankan deals, worked end-to-end. Plug each set of inputs into the calculator above — the headline numbers should match to the rupee.

• CBSL — Monetary Board Direction No. 1 of 2023 (maximum lending rates)
• Finance Leasing Act No. 56 of 2000
• Inland Revenue Act No. 24 of 2017 — Schedule 4 (capital allowances for leased vehicles)
• Central Bank of Sri Lanka — official site

This calculator's ceiling constant and methodology were last cross-checked against the CBSL direction on 2026-05-17. The page is reviewed each time a successor direction is issued and after any amendment to the Finance Leasing Act.