Credit Card Interest: What Unpaid Balances Really Cost
Leaving ৳50,000 unpaid for 6 months at 25% adds about ৳6,585 in interest (৳56,585 owed). Paying only the minimum takes about 7 years instead. Try your figures below.
৳
= 50 thousand taka
%
Bangladesh Bank caps card interest at 25% a year. Higher rates show a warning.
months
= 6 months
Total owed with interest
৳56,585
6 months
Unpaid balance
৳50,000
Compound interest
৳6,585
Total owed with interest
৳56,585
Time to clear on minimum payments
6 years 7 months
Total interest on minimum payments
৳30,651
Leaving ৳50,000 unpaid for 6 months adds ৳6,585 in interest, for ৳56,585 owed in total. The trap: paying 5% of the bill or ৳500 (whichever is higher) each month takes 6 years 7 months to clear and costs ৳30,651 in interest.
Bangladesh Bank rules (16 March 2026) cap card interest at 25% a year. Please check the rate.
Card interest compounds monthly on the unpaid balance only. Minimum-payment rules differ by bank — this is an estimate.
How this was calculated
Monthly compounding: total = ৳50,000 × (1 + 25% ÷ 12)ⁿ, n = 6 months = ৳56,585
Minimum payment: after interest each month, pay 5% of the bill or ৳500 (whichever is higher)
Enter the bank's annual interest rate (at most 25%).
Choose how many months it stays unpaid — 1, 3, 6 or 12.
The total owed with interest and the minimum-payment trap update instantly.
The interest formula
Total owed = balance × (1 + r)ⁿ
r = monthly rate = annual rate ÷ 12 ÷ 100
n = months left unpaid
Interest = total − balance
Minimum-payment estimate: each month interest is added, then 5% of the bill or ৳500 (whichever is higher) is paid — the months and interest this takes is the trap calculation.
Paying only the minimum (5% or ৳500) takes about 7 years (79 months) and costs about ৳30,651 in interest — nearly 5× the 6-month interest.
Things to watch
25% maximum rate: under Bangladesh Bank rules (from 16 March 2026) card interest cannot exceed 25% a year. Question any higher rate.
The minimum-payment trap: the minimum avoids penalties but doesn’t stop interest. Pay the full bill whenever you can.
Interest-free period: new purchases usually get 15–45 interest-free days if the full bill is paid on time. Cash withdrawals get no grace period — interest starts on day one.
More: when carrying a balance hurts most
Because interest compounds on the balance, bigger balances grow faster. And because the minimum is a percentage of the bill, payments shrink as the balance shrinks — the last taka takes the longest to clear. So paying extra while the balance is still large saves the most.
Frequently asked questions
How is interest charged on card balances?
Only on the unpaid balance, compounding every month. Total = balance × (1 + annual rate ÷ 12)ⁿ, where n = months. For example, ৳50,000 at 25% for 6 months grows to ৳56,585.
What is the maximum card interest rate?
Under Bangladesh Bank's 16 March 2026 policy, card interest is capped at 25% a year. The calculator warns you if you enter a higher rate.
What happens if I only pay the minimum?
Full interest keeps running on the rest. On ৳50,000 at 25%, paying 5% of the bill or ৳500 each month takes about 7 years to clear and costs about ৳30,651 in interest.
How much interest on ৳50,000 left for 6 months?
At 25% a year with monthly compounding, about ৳6,585 — ৳56,585 owed in total. At 0% (e.g. paid within the grace period) the total is just the balance.
Are minimum-payment rules the same at every bank?
No — usually 3–5% of the bill or a floor like ৳500, whichever is higher. This calculator assumes 5% or ৳500; check your own card's terms.