The Real Cost of Card Borrowing in Singapore
Singapore credit cards come with two very different ways to spread a cost. An instalment plan converts a purchase into equal monthly payments, usually marketed as 0% interest — but almost always carrying a one-time processing fee. A revolving balance is what happens when you pay less than the full statement amount: the remainder attracts the card's published rate, compounded monthly, with a minimum payment designed to keep the balance alive. The two have almost nothing in common mathematically, which is why this page has two modes.
Why a 0% instalment plan still has an interest rate
The processing fee is paid up front on the whole purchase, while the value is returned to you month by month. That timing gap is exactly what an interest rate measures. With the example inputs — S$5,000 over 12 months at the illustrative 3.00% fee — you pay S$150 for the plan, but because the average balance outstanding across the year is only about half the purchase, the money is working at roughly double the headline percentage: the effective interest rate computes to about 5.6% p.a. Issuers are required to disclose effective interest rates on plan terms in Singapore — the number on your terms sheet governs, and this page lets you check it independently.
The revolving trap, quantified
Revolving balances compound against you. At the illustrative 20.00% rate, a S$5,000 balance paying the example minimum — 3% of the balance or S$50 — takes about eleven years to clear and costs nearly S$5,000 again in interest. Fix the payment at S$300 instead and the same balance clears in 20 months at a fraction of the cost. Both simulations run live below; the difference between them is the single most expensive decision on this page. Paying the full statement balance by the due date avoids interest entirely — that is the structure Singapore cards reward.
What the calculator leaves out
Late fees, cash-advance charges, and the issuer-specific quirks of how minimum payments are actually computed are not modelled — issuers differ, and the figures on your statement govern. The minimum-payment fields here are editable examples precisely because there is no universal formula. Balance transfers with interest-free windows are a different product with a different maths; the Singapore Debt Consolidation Calculator is the better starting point for those.
Frequently Asked Questions
What does EIR mean here?
Effective interest rate: the annualised rate that equates the value you receive (the purchase amount) with the payments you make (instalments including the processing fee). Singapore issuers disclose EIR on credit products because headline percentages understate the true cost — this calculator computes it from your own inputs, independently.
Why does a 3% fee produce a rate above 3%?
Because you pay the fee up front on the full amount while receiving the value back over the plan's months. The average outstanding balance is roughly half the purchase, so the fee's cost per dollar actually deployed is about double its headline percentage.
Are the minimum-payment fields my issuer's real formula?
No — they are editable examples (3% of balance, S$50 floor by default). Issuers set their own minimums and change them; enter the figures from your own statement for a meaningful simulation.
Is paying the minimum ever sensible?
Only as a short bridge. The minimum is designed to avoid default, not to clear the debt — at the example inputs the balance takes about eleven years and costs nearly as much again in interest. If you cannot clear the balance quickly, a personal loan or a structured consolidation at a lower rate is usually the better maths; the Debt Consolidation Calculator compares them.
Do instalment plans affect my credit limit?
Generally the plan amount is held against your limit until the instalments complete, though the exact treatment varies by issuer — check your issuer's terms. The calculator does not model limits or bureau effects.
Related Singapore Calculators
- Singapore Debt Consolidation Calculator — one loan replacing many card debts
- Singapore Personal Loan Calculator — the alternative to revolving debt
- Singapore Loan Affordability Calculator — total debt service that fits
- Singapore Loan Repayment Calculator — schedules and extra-payment savings
Disclaimer: Finance Atlas is not a bank, licensed moneylender, finance company, card issuer or financial adviser in Singapore. This calculator provides educational estimates only and does not constitute financial advice, a credit offer or a recommendation of any product. Confirm exact figures, rates, fees and eligibility criteria with your lender, issuer or bank.