Credit Card Interest Calculator (USA)

Use GlobalCalqulate’s free Credit Card Interest Calculator (USA, 2026) to estimate how much interest you pay on credit card balances based on APR, balance, and monthly payments. Calculate monthly interest charges, total interest cost, and payoff timeline. Supports common scenarios like minimum payments, extra payments, and comparing two cards to find the cheapest payoff strategy.

Last revised 13 September 2026

By Team GlobalCalqulate · About our editorial standards

Credit Card Balance

Current Credit Card Balance

Interest & APR

Standard Purchase APR

Monthly Payment Strategy

Monthly Payment

Extra Monthly Payment

Minimum Payment Percentage

Total Interest Paid

$4,512.50

Payoff Time: 31 months

Financial Disclaimer: This result is an educational estimate produced by applying a standard formula to the figures you entered. It is not an offer, a quotation, or financial advice: real costs and returns depend on a provider's pricing, fees and underwriting, and on circumstances this calculator does not collect. Confirm the figures with the provider or a qualified adviser before acting on them. Full disclaimer.

Sources & methodology

Reference:: Consumer Financial Protection Bureau
Data source:: Board of Governors of the Federal Reserve System

Calculation type: Exact calculation. Figures are taken from Consumer Financial Protection Bureau and Board of Governors of the Federal Reserve System — see sources below.

Your entries stay on this device. This calculator runs entirely in your browser — the figures you type are not sent to us or to anyone else. The page itself uses cookies for analytics and advertising, described in the privacy policy.

Formula & methodology

Limitations

Assumes a single fixed APR for the whole balance. Most cards apply different APRs to purchases, cash advances and balance transfers simultaneously.
Promotional zero-interest periods and their expiry are not modelled.
Interest is calculated on the balance you enter. Real cards compound daily on an average daily balance, and new purchases change it every month.
Penalty APR after a late payment, annual fees, late fees and cash-advance fees are not included.
Assumes no new spending on the card during the payoff period.
An estimate. Your cardholder agreement governs how interest is actually charged.

This page is educational. It applies a standard formula to the figures you enter and shows the arithmetic behind the result. It is an estimate, not an offer, a quotation or financial advice: real costs depend on the provider's pricing, fees and underwriting, and on circumstances this calculator does not collect.

Sources & references

Regulation12 CFR § 1026.7 — Periodic statement (minimum payment and payoff disclosures) — Consumer Financial Protection Bureau
Requires the minimum-payment warning and payoff estimate printed on every US card statement — the same calculation this page performs from your balance and APR.
Reference dataConsumer Credit — G.19 statistical release (credit card interest rates) — Board of Governors of the Federal Reserve System
The official series for average US credit card APRs, for checking whether the rate you entered is typical.

Financial Disclaimer: This calculator estimates interest charges using the APR and balance you enter; it does not account for daily periodic rate variations, promotional APR periods, cash advance rates, penalty APRs, or annual fees your card issuer may charge. Actual interest charged by your card issuer may differ. This tool is for planning purposes only and is not financial advice — consult your card agreement or issuer for exact terms. Full disclaimer.

Help & FAQs

Frequently Asked Questions

Clear answers to common questions to help you use this calculator confidently.

How does this Credit Card Interest Calculator work?

Tap to view the answer

It uses your current balance, APR, and monthly payment to estimate the interest you'll pay over time. Issuers typically apply a daily periodic rate rather than the simple-interest math shown here, so treat the result as a close estimate, not your exact statement balance.

Does this account for the CARD Act rules on penalty APRs and fees?

Tap to view the answer

The CARD Act (2009) caps penalty APRs (typically 25-29%) and requires clear disclosures, but penalty APRs, late fees ($25-$35), and annual fees aren't included in this calculator's math — add them manually if they apply to your card to get a realistic total cost.

What happens if I only pay the minimum?

Tap to view the answer

Enter your card's minimum payment to see how slowly the balance shrinks and how much of each payment goes to interest versus principal — this is usually the scenario that reveals the true cost of carrying a balance.

How much do extra or one-time payments reduce my interest?

Tap to view the answer

Increasing your monthly payment or applying a lump sum reduces the balance interest accrues on going forward, which shortens payoff time and cuts total interest paid. Re-run the calculator with a higher payment to see the difference.

Does a promotional 0% APR period get modeled here?

Tap to view the answer

No — enter your standard ongoing APR. If your card has a temporary 0% promo rate, calculate the promo period separately and then re-run this calculator with the regular APR for after it expires, since paying only the minimum through a promo period can leave a large balance once interest resumes.

Need more help? Contact support or email globalcalqulate@gmail.com

We typically reply within 24–48 hours.

How this credit card interest calculator works

Credit card issuers apply a daily periodic rate (APR ÷ 365) to your average daily balance. This calculator shows the total interest cost and payoff timeline when you make minimum payments, fixed payments or a custom amount.

Derive the monthly interest charge: (APR ÷ 12) × current balance.
Determine the minimum payment (typically 1–2 % of outstanding balance or a fixed floor).
Apply each payment: interest is charged first; the remainder reduces principal.
Iterate month by month to produce the total interest paid and the months to payoff.

Results assume a fixed APR with no new charges. Issuers may change rates. Always review your card agreement for exact terms.

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How to Use This Calculator

Enter your card balance and APR

Use the APR shown on your credit card statement.

Choose your payment method

Enter a fixed payment or rely on minimum payment rules.

Add extra payments

Extra payments significantly reduce interest and payoff time.

Review interest and payoff timeline

See how long it takes to eliminate your balance.

US Credit Card Interest Calculator – Complete Guide (2026)

How Credit Card Interest Is Calculated

Most US credit cards use a daily periodic rate based on APR.

Minimum Payments Explained

Minimum payments primarily cover interest, slowing payoff.

Why APR Matters

Higher APR dramatically increases the total cost of debt.

Strategies to Reduce Interest

Extra payments and balance transfers can lower costs.

Formula & methodology

Limitations

Assumes a single fixed APR for the whole balance. Most cards apply different APRs to purchases, cash advances and balance transfers simultaneously.
Promotional zero-interest periods and their expiry are not modelled.
Interest is calculated on the balance you enter. Real cards compound daily on an average daily balance, and new purchases change it every month.
Penalty APR after a late payment, annual fees, late fees and cash-advance fees are not included.
Assumes no new spending on the card during the payoff period.
An estimate. Your cardholder agreement governs how interest is actually charged.

Sources & references

Regulation12 CFR § 1026.7 — Periodic statement (minimum payment and payoff disclosures) — Consumer Financial Protection Bureau

Requires the minimum-payment warning and payoff estimate printed on every US card statement — the same calculation this page performs from your balance and APR.

Reference dataConsumer Credit — G.19 statistical release (credit card interest rates) — Board of Governors of the Federal Reserve System

The official series for average US credit card APRs, for checking whether the rate you entered is typical.

Calculator inputs

Credit Card Balance

Interest & APR

Monthly Payment Strategy

Your results

Sources & methodology

Formula & methodology

Limitations

Sources & references

How does this Credit Card Interest Calculator work?

Does this account for the CARD Act rules on penalty APRs and fees?

What happens if I only pay the minimum?

How much do extra or one-time payments reduce my interest?

Does a promotional 0% APR period get modeled here?

How this credit card interest calculator works

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More United States calculators

Popular US Calculators

Calculator inputs

Credit Card Balance

Interest & APR

Monthly Payment Strategy

Your results

Sources & methodology

How to Use This Calculator

Example Credit Card Payoff

Understanding Your Results

Key Tips

US Credit Card Interest Calculator – Complete Guide (2026)

How Credit Card Interest Is Calculated

Minimum Payments Explained

Why APR Matters

Strategies to Reduce Interest

Formula & methodology

Limitations

Sources & references

How to Use This Calculator

Example Credit Card Payoff

Understanding Your Results

Key Tips

US Credit Card Interest Calculator – Complete Guide (2026)

How Credit Card Interest Is Calculated

Minimum Payments Explained

Why APR Matters

Strategies to Reduce Interest