Credit Card Calculator

Quick answer

The credit card calculator works out how long it takes to pay off a credit card balance and the total interest – paying a fixed amount or the card's minimum payment – and how much faster you'd be debt-free with an extra payment.

$
%
$
$
First month's interest
$ —
Months to pay off – planned payment
—
Interest – planned payment
$ —
Months to pay off – with extra payment
—
Interest – with extra payment
$ —
Interest saved
$ —
Total paid with extra payment
$ —

Paying only the minimum keeps you in debt for years and multiplies the cost. Pay more than the minimum, pay in full whenever possible, and avoid cash advances, which charge a higher APR from day one.

How to use the Credit Card Calculator

  1. Credit card balance
  2. APR
  3. Monthly payment
  4. Additional monthly payment

Results update as you type, and every field accepts the units shown in its menu.

How it works

Enter the balance, APR, the monthly payment you plan to make and any extra payment.

Tips

  • Compare loans by APR and total cost, not just the monthly payment.
  • Extra payments go straight to principal and can save a lot of interest.
  • Pay off the highest-rate debt first if you want to save the most money.
  • Check for prepayment penalties before paying a loan off early.

Common mistakes to avoid

  • Stretching a loan term to lower the payment without seeing the extra interest.
  • Paying only the minimum on credit cards.
  • Forgetting fees that are rolled into the loan.

Inputs explained

Field What to enter
Credit card balance Amount in your currency
APR In %
Monthly payment Amount in your currency
Additional monthly payment Amount in your currency

What each result means

  • First month’s interest = [Credit card balance]×[APR]÷1200
  • Months to pay off – planned payment = nper([APR]÷1200, [Monthly payment], [Credit card balance])
  • Interest – planned payment = [Monthly payment]×[Months to pay off – planned payment] – [Credit card balance]
  • Months to pay off – with extra payment = nper([APR]÷1200, [Monthly payment] + [Additional monthly payment], [Credit card balance])
  • Interest – with extra payment = ([Monthly payment] + [Additional monthly payment])×[Months to pay off – with extra payment] – [Credit card balance]
  • Interest saved = [Interest – planned payment] – [Interest – with extra payment]
  • Total paid with extra payment = ([Monthly payment] + [Additional monthly payment])×[Months to pay off – with extra payment]

Example values

How the main result changes when Credit card balance changes and everything else stays at the example values above:

Credit card balance Months to pay off – with extra payment
2,500 14
3,750 23
5,000 34
6,250 48
7,500 67
10,000 167

Formula

Monthly interest = balance × APR ÷ 12Months to pay off (fixed payment) = −log(1 − B × i ÷ P) ÷ log(1 + i)Minimum payment = max(minimum $, balance × minimum %)

Worked example

Inputs — Credit card balance: $5,000; APR: 22.99 %; Monthly payment: $150; Additional monthly payment: $50.
Results — First month's interest = $95.79; Months to pay off – planned payment = 54; Interest – planned payment = $3,044.95; Months to pay off – with extra payment = 34; Interest – with extra payment = $1,870.64; Interest saved = $1,174.31; Total paid with extra payment = $6,870.64.

Frequently asked questions

How long will it take to pay off my credit card?

Divide the balance by what you pay after interest – this calculator does it exactly.

How is credit card interest calculated?

Daily on the average daily balance, at APR ÷ 365.

What is a good credit card APR?

Average APRs are over 20%; under 15% is low for a standard card.

What formula does the Credit Card Calculator use?

Monthly interest = balance × APR ÷ 12.

Sources

  1. Consumer Financial Protection Bureau

Cite this calculator

Speedy Calculator. (2026). Credit Card Calculator. Speedy Calculator. https://speedycalculator.com/calculators/finance/credit-card/