How Often Does Interest Accrue: Daily or Monthly?

Interest usually accrues daily on credit cards, student loans, auto loans, HELOCs, and most savings accounts, while traditional fixed-rate mortgages accrue interest monthly. How often interest accrues on your account controls whether paying a few days early actually reduces your cost, and it is the single most useful thing to know about any loan or deposit you hold.

Daily vs. Monthly Accrual

When interest accrues daily, the lender takes your annual percentage rate, divides it by the number of days in the year to get a daily periodic rate, and multiplies that rate by your outstanding balance each day. On a $10,000 balance at 8.5% APR, the daily interest charge works out to about $2.33. Send a payment a week before the due date and the following day’s interest is calculated on a smaller balance.

Monthly accrual works differently. The lender runs the calculation once per period, applying one-twelfth of your annual rate to the balance at a set point in the month. The balance you carry on day two is the same balance used on day twenty-seven, so paying early within a month does nothing for that month’s interest charge. Traditional mortgages work this way.

The practical takeaway: on daily-accrual accounts, timing and extra payments matter. On monthly-accrual accounts, they generally do not change the current period’s interest, though they still reduce principal going forward.

Accrual Is Not the Same as Compounding

Accrual is the calculation that tells you how much interest has built up. Compounding is the separate moment when that accrued interest gets folded into your principal so future interest is charged on the new, larger balance. A loan can accrue daily and compound monthly, which keeps the interest-on-interest effect from kicking in every single day.

Compounding frequency has a real impact on the total you pay or earn. A 5% rate that compounds daily produces a higher effective annual cost than a 5% rate that compounds annually, because each day’s interest starts generating its own interest. Regulation DD, which implements the Truth in Savings Act, requires banks to express this effect as the annual percentage yield (APY) so you can compare deposit accounts on equal terms.¹ The APY formula accounts for both the interest rate and the compounding frequency over a 365-day period.² For borrowers, the equivalent disclosure is the APR. Comparing APY on deposits and APR on loans is more reliable than comparing stated rates alone.

How Interest Accrues on Each Type of Account

Credit Cards

Credit card issuers accrue interest daily using a daily periodic rate — your APR divided by 365 — applied to your average daily balance for the billing cycle.³ For each day in the cycle, the issuer takes your balance (new charges added, payments subtracted), multiplies by the daily periodic rate, and records a charge. The daily charges are totaled at the end of the cycle and added to your statement.

On a $5,000 balance at 22% APR, the daily periodic rate is about 0.0603%. Roughly $3.01 in interest accrues every day you carry that balance, which comes to about $90 over a 30-day cycle. The next cycle’s interest is calculated on the new, larger balance.

Most cards offer a grace period, a window during which new purchases do not accrue interest at all. If you pay your full statement balance by the due date, the issuer cannot charge interest on those purchases, and federal law requires your statement to be sent at least 21 days before the grace period ends.⁴ The grace period usually disappears once you carry a balance from one cycle to the next, and interest begins accruing on new purchases from the day they post. Issuers cannot charge retroactive interest on balances you already repaid within the grace period.⁵

Mortgages

Traditional fixed-rate mortgages accrue interest monthly. The lender divides your annual rate by 12 and applies the monthly rate to your outstanding principal at the start of each period. Because the calculation happens once, paying a few days early inside the same month does not reduce that month’s interest.

Mortgage interest is also paid in arrears. Each monthly payment covers the interest that built up during the previous month, so your February payment covers January’s interest. This is why closing on a home purchase involves a prepaid interest charge covering the days between closing and the end of that month; your first regular payment is not due until the following month.

Some newer mortgages, often marketed as “simple interest” mortgages, do accrue daily. On those loans, paying a few days early each month can save real money over a 30-year term because principal drops sooner and each subsequent day’s interest is lower.

Student Loans

Federal student loans use daily simple interest. The formula multiplies your outstanding principal by an interest rate factor (your rate divided by the number of days in the year), then by the number of days since your last payment.⁶ For loans first disbursed between July 1, 2025, and June 30, 2026, fixed rates are 6.39% for undergraduate Direct Loans, 7.94% for graduate Direct Unsubsidized Loans, and 8.94% for Direct PLUS Loans.⁷ Because the accrual runs daily, extra payments or more frequent payments shrink principal faster and lower total interest over the life of the loan.

Student loan interest does not automatically compound the way credit card interest does. Accrued but unpaid interest sits separately from your principal until a triggering event causes it to capitalize, meaning get added to principal. For Direct Loans managed by the Department of Education, capitalization happens after a deferment period on an unsubsidized loan, or when you leave or no longer qualify for income-based repayment.⁶ Once interest capitalizes, your higher principal generates more daily interest going forward.

Auto Loans

Auto loans fall into two camps that handle accrual differently.

Simple interest auto loans accrue interest on your actual outstanding balance, either daily or monthly. Paying more than the minimum or paying early shrinks the principal faster and reduces total interest.
Precomputed interest auto loans calculate all the interest you will owe over the full term upfront and bake it into the payment schedule. Extra payments do not reduce principal or the total interest owed.

The distinction matters most if you plan to pay off the loan early.⁸ On a simple-interest loan, an extra $100 toward principal means less interest accrues the following day. On a precomputed loan, that extra $100 has no effect on the interest already locked in. Check your contract before committing to an early-payoff strategy.

HELOCs

Home equity lines of credit accrue daily using a method similar to credit cards. The lender takes your average daily balance, multiplies by your interest rate, divides by 365, and multiplies by the number of days in the billing cycle. HELOCs usually carry variable rates tied to the prime rate plus a margin, so the daily interest charge can change from month to month even if you do not draw additional funds.

Savings Accounts and CDs

Savings accounts and certificates of deposit typically accrue interest daily but credit it to your account monthly. A CD with a $10,000 principal earns a small amount each day, but the balance only moves on the monthly crediting date. Regulation DD requires banks to disclose both the compounding frequency and the crediting frequency.¹

The gap between accrual and crediting matters if you withdraw early. Interest that has accrued but not yet been credited may be forfeited, and CDs typically carry an early withdrawal penalty on top of that. Check the crediting schedule before pulling money out of a time-deposit account.

The 360-Day Year vs. the 365-Day Year

Daily accrual sounds simple, but lenders do not all use the same number of days to divide your APR. The 365-day method (actual/365) uses the real calendar count. The 360-day method, sometimes called the “banker’s year,” assumes twelve 30-day months and produces a slightly higher daily rate because the same annual interest gets spread over fewer days.

The gap looks small per day and gets large over time. On a $300,000 mortgage at 7%, using a 360-day year instead of 365 adds roughly $1.15 more in daily interest. Across 30 years, that compounds. Your loan documents state which method applies.

In a leap year, lenders using the 365-day method generally switch to 366 days for that calendar year, which slightly lowers the daily rate. Lenders using the 360-day method ignore leap years, since the calculation is not tied to real calendar days.

Where to Confirm Your Accrual Terms

Every consumer financial product comes with disclosures spelling out exactly how interest is calculated, how often it compounds, and whether a grace period applies.

Credit cards: the disclosure table (often called the Schumer Box) in your card agreement shows your APR, the balance calculation method, and the grace period length in a standardized format required by federal law.⁹
Mortgages: the Loan Estimate discloses the loan product type, rate, and projected payments; the promissory note specifies whether the lender uses a 360-day or 365-day year.¹⁰
Savings accounts and CDs: the account disclosure you received at opening must state compounding frequency, crediting frequency, and APY.¹
Student loans: your servicer’s website and your Master Promissory Note list the interest rate, accrual method, and capitalization triggers.
Auto loans: your retail installment contract states whether the loan uses simple or precomputed interest, along with the APR and payment schedule.

If you cannot locate these documents, request them from your lender or servicer. Federal law requires them to provide the information, and having it in hand is the only way to verify exactly how your balance is growing each day.

1
eCFR. 12 CFR Part 1030 – Truth in Savings (Regulation DD)
2
Legal Information Institute. Appendix A to Part 1030 – Annual Percentage Yield Calculation
3
Consumer Financial Protection Bureau. How Does My Credit Card Company Calculate the Amount of Interest I Owe?
4
eCFR. 12 CFR 1026.5 – General Disclosure Requirements
5
Consumer Financial Protection Bureau. 12 CFR 1026.54 – Limitations on the Imposition of Finance Charges
6
Federal Student Aid. Federal Interest Rates and Fees
7
Federal Student Aid Partners. Interest Rates for Direct Loans First Disbursed Between July 1, 2025 and June 30, 2026
8
Consumer Financial Protection Bureau. What’s the Difference Between a Simple Interest Rate and Precomputed Interest on an Auto Loan
9
Office of the Law Revision Counsel. 15 USC 1637 – Open End Consumer Credit Plans
10
eCFR. 12 CFR 1026.37 – Content of Disclosures for Certain Mortgage Transactions (Loan Estimate)