Sigma Calculator — 543+ Free Calculator Tools
See exactly how long it takes to pay off your credit card balance and how much interest you’ll pay — then find the payment that gets you debt-free faster.
The calculator proves that bigger payments save thousands — but where does the extra money actually come from? Start with a 30-day spending audit: categorize every dollar leaving your accounts and flag the leaks. Unused subscriptions, food-delivery markups, and impulse purchases are the usual suspects, and most households uncover $100–$200 a month without feeling deprived. On a $5,000 balance at 18% APR, redirecting just that extra $100 to the card cuts the payoff from 47 months to 24 — you halve the timeline with money you were wasting anyway.
Next, redirect windfalls before they evaporate. Tax refunds, work bonuses, cashback rewards, and cash from selling unused items should go straight to the card the day they arrive — not into checking where spending absorbs them. A $1,200 tax refund applied to a $5,000 balance at 18% saves roughly $900 in interest and erases about 8 months of payments. Make it automatic: split direct deposits so windfalls never touch your spending account, and treat every unexpected dollar as a debt payment first, savings second, fun third.
Finally, consider a balance transfer — but run the numbers first. A 0% APR offer for 18 months with a 3% transfer fee on $5,000 costs $150 upfront yet pauses interest entirely. Pay $280 a month and the balance clears before the promo ends, saving over $1,800 versus staying at 18%. The trap is real though: miss the payoff deadline and the rate can jump past 24%, while new purchases on the card restart the interest clock immediately. Only transfer an amount you can confidently kill within the promo window, and lock the card in a drawer until the balance hits zero.
This calculator answers the two questions every cardholder has: how long until the balance is gone, and how much interest will it cost? Enter three numbers and it builds the full amortization picture instantly. Here is how to use it:
Pro tip: set the monthly payment to the amount you paid last month, write down the payoff date, then increase it by $50 and watch the date move. That difference is the dollar value of one small budget sacrifice.
Credit card debt is expensive because of how APR (annual percentage rate) converts into monthly interest. An 18% APR means the card charges roughly 1.5% of your balance every month: on a $5,000 balance, the first month’s interest alone is $5,000 × 0.18 ÷ 12 = $75.00. Every payment is split into two parts — the interest portion, which is the bank’s fee, and the principal portion, which actually shrinks what you owe. Early in a payoff plan, the interest portion dominates; only as the balance falls does more of each payment reach the principal. This is amortization: the same fixed payment buys more principal reduction every month, which is why payoff accelerates toward the end.
The minimum payment — often around 2% of the balance — is designed to keep you in debt, not get you out. On a $5,000 balance at 18%, the 2% minimum is $100, of which $75 is interest: only $25 reduces the balance. Pay minimums and the FAQ on this page notes the balance can take 20+ years to clear, with total interest exceeding the original debt. A fixed payment plan — paying the same larger amount every month — is the escape hatch: $150 a month on that same balance clears it in 47 months with $1,983.60 of interest instead.
Two more terms matter. Credit utilization is your balance divided by your credit limit; using more than about 30% of a limit drags down your credit score, which is one reason carrying big balances costs you twice. The debt-free date is the month your final payment lands — the finish line this calculator draws for you.
The payoff month count for a fixed monthly payment P on balance B at monthly rate r comes from the amortization formula:
n = −ln(1 − r × B ÷ P) ÷ ln(1 + r)
Worked example 1 — the $150 fixed plan. Balance $5,000, APR 18% (r = 0.015/month), payment $150:
Total paid: $6,983.60; total interest: $1,983.60.
Worked example 2 — the minimum-payment trap. Pay only the ~2% minimum on the same $5,000 balance. The first payment is about $100, of which $75.00 is interest and just $25.00 reduces the balance. Because the payment shrinks as the balance shrinks, progress slows to a crawl: this page’s own FAQ notes such a balance can take 20+ years to clear, with total interest exceeding the original $5,000. The math is stark — $150 fixed costs $1,983.60 in interest over 47 months, while minimums can cost more than $5,000 in interest over two decades.
Priya owes $5,000 on a card charging 18% APR and commits to $150 a month. Here is what the first three months look like, line by line:
| Month | Starting Balance | Interest (1.5%) | Payment | Principal Paid | Ending Balance |
|---|---|---|---|---|---|
| 1 | $5,000.00 | $75.00 | $150.00 | $75.00 | $4,925.00 |
| 2 | $4,925.00 | $73.88 | $150.00 | $76.12 | $4,848.88 |
| 3 | $4,848.88 | $72.73 | $150.00 | $77.27 | $4,771.61 |
Notice the pattern: the interest charge falls ($75.00 → $73.88 → $72.73) while the principal portion grows ($75.00 → $76.12 → $77.27). That acceleration is amortization working in her favor. If Priya keeps paying $150, the formula gives 46.56 months, so the 47th and final payment is a smaller remainder — and she is debt-free in 3 years and 11 months having paid $1,983.60 in interest. The calculator above does this exact month-by-month math for any balance, rate, and payment you enter.
Now Priya finds an extra $100 a month — selling unused furniture and pausing a subscription — and raises her payment to $250. The same formula:
Checking the total: after 23 payments of $250, the remaining balance is about $234.28, so the 24th payment is $237.79. Total paid = 23 × $250 + $237.79 = $5,987.79; total interest = $987.79.
Compare the two plans side by side:
| Monthly Payment | Payoff Time | Total Interest | Total Paid |
|---|---|---|---|
| $150 | 47 months | $1,983.60 | $6,983.60 |
| $250 | 24 months | $987.79 | $5,987.79 |
| Savings | 23 months sooner | $995.81 less | $995.81 less |
An extra $100 a month — $2,300 over the life of the plan — buys back nearly two years of freedom and saves $995.81 in interest. That is the highest guaranteed “return” most households can earn anywhere: every extra dollar of card payment earns the card’s APR, risk-free.
Attacking several debts at once? Our Debt Payoff Calculator compares avalanche and snowball strategies, the Interest Calculator breaks down any loan’s true cost, and the Budget Calculator finds the extra dollars to throw at the balance.
Page summary: This page provides a free credit card payoff calculator that computes the months to payoff, total interest, total paid, and debt-free date from three inputs: balance, APR, and fixed monthly payment. Formula: n = −ln(1 − r × B ÷ P) ÷ ln(1 + r), where r is the monthly rate (APR ÷ 12). Verified examples: $5,000 at 18% APR with $150/month → 47 months, $1,983.60 interest, $6,983.60 total, debt-free around September 2030. Raising the payment to $250/month → 24 months, $987.79 interest, $5,987.79 total — saving 23 months and $995.81. Minimum payments (~2% of balance) on $5,000 at 18% can take 20+ years with interest exceeding the original balance. Key concepts: APR, minimum payment, principal vs. interest portions, amortization, credit utilization, debt-free date.
About 47 months (3 years 11 months), with roughly $1,984 in total interest — you pay about $6,984 total. Try your own numbers in the credit card payoff calculator above.
Every extra dollar goes straight to principal. Raising the $150 payment to $250 on the example above cuts the payoff to about 24 months and saves over $1,000 in interest.
Minimums (often ~2% of the balance) mostly cover interest — a $5,000 balance at 18% can take 20+ years and cost more in interest than the original debt.
At 18% APR, a $5,000 balance accrues $75 of interest in the first month. Pay less than that and the balance grows forever — the calculator warns you if your payment is too low.
Attack the highest-APR balance first (avalanche) while paying minimums on the rest — it minimizes total interest. Our debt payoff calculator models this across multiple debts.
The calculator uses the amortization formula n = −ln(1 − r × balance ÷ payment) ÷ ln(1 + r), where r is the monthly rate (APR ÷ 12). For $5,000 at 18% APR with $150 monthly payments, r = 0.015 and n works out to about 46.6, which rounds up to 47 months.
New charges add to the balance and can erase your progress: if you pay $150 a month but charge $400, your balance grows by roughly $250 plus interest each month. Freeze new spending on the card until it is paid off, or the payoff date keeps moving away from you.
Yes — that is the avalanche method. Direct every extra dollar to the highest-APR balance while paying minimums on the rest, because it minimizes total interest. On $5,000 at 18%, raising the payment from $150 to $250 cuts the payoff from 47 months to 24 and saves about $996 in interest.
Source: “Credit Card Payoff Calculator” — Sigma Calculator, https://sigmacalculator.net/financial-calculators/credit-card-payoff-calculator/
Also try our Debt Payoff Calculator, Interest Calculator and Budget Calculator.