Calculate time and interest to pay off credit card balances with minimum payment analysis and extra payment impact charts.
A credit card balance can linger because each payment first covers accrued interest and only the remainder reduces principal. This planner projects the number of monthly payments, total interest, and payoff timing for a minimum-payment path, then compares those results with an added monthly amount. Its chart shows how the balance changes under each plan. A common source of confusion is that a statement minimum is not necessarily a fixed-payment plan; the required amount can change as the balance changes.
A concrete input and expected output from the current implementation.
Input
Balance: $1,000; APR: 0%; minimum monthly payment: $100; extra monthly payment: $100
Expected output
Minimum only: 10 months, $0 interest, $1,000 total paid. With extra: 5 months, $0 interest, $1,000 total paid. Difference: 5 months sooner and $0 interest saved.
At 0% APR, every dollar paid reduces principal. $1,000 / $100 = 10 monthly payments, while $1,000 / ($100 + $100) = 5 monthly payments.
Starting from the entered balance and APR, the calculator builds a monthly payoff schedule. Each projected payment covers that period's interest before reducing principal, and the sequence ends when the balance reaches zero. The final payment may be smaller than the regular amount. The reported elapsed time and accumulated interest summarize the resulting schedule.
The baseline represents paying the specified minimum, while the comparison adds the entered extra amount to each monthly payment. The planner charts the two balance paths and summarizes their time and interest differences. When the extra amount is zero, the paths coincide. At a zero APR, extra payments shorten the schedule but cannot produce interest savings.
Because the extra amount reduces principal earlier, later interest is charged against a smaller projected balance. That feedback can remove several payments, especially when the baseline payment is close to the interest charge. At 0% APR, however, the benefit is time only; the interest saving is necessarily zero.
Not necessarily. Statements may use daily balance methods, different posting dates, changing minimums, fees, new purchases, promotional rates, or rate changes. A planner with stable inputs is a projection, not an issuer quote. Use the card issuer's current payoff amount when the account must be paid in full on a particular date.
The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.
Calculate gross, operating, and net profit margins from cost and revenue with breakeven analysis.
Convert between annual salary and hourly rate with adjustments for work hours, overtime, and benefits.
Calculate sales tax amounts, tax-inclusive and tax-exclusive prices for any tax rate or jurisdiction.
Calculate return on investment from initial cost and final value with annualized ROI and comparison tables.
Convert between markup and margin percentages, calculate selling price, and compare pricing strategies.
Convert numeric amounts to written words for invoices, checks, and legal documents in multiple currencies.