What Is the Average Daily Balance Method? (2026)

The mechanics of the ADB method

The ADB calculation runs every day of the billing cycle. Step by step:

1. The issuer records your ending balance for each day in the billing cycle.
2. New purchases posted that day are added to the daily balance.
3. Payments posted that day are subtracted from the daily balance.
4. At cycle close, the issuer sums every daily ending balance.
5. The sum is divided by the number of days in the cycle (typically 28 to 31).
6. The resulting ADB is multiplied by the daily periodic rate and then by days in cycle, producing the finance charge.

The legal basis is Regulation Z, 12 CFR 1026.7(b)(5), which requires issuers to disclose the balance computation method on every periodic statement. The CFPB’s interest calculation explainer describes the same method.

Including new purchases vs excluding new purchases

The standard ADB method is “average daily balance including new purchases.” This is what Chase, Citi, Capital One, Bank of America, and Discover use on virtually all consumer cards. New purchases that post during the cycle increase ADB starting from their posting date.

A few cards use “average daily balance excluding new purchases.” Under this variant, new purchases do not enter ADB until the NEXT cycle. The consumer benefit is that purchases get an automatic one-cycle interest-free runway even if grace period is lost. The method is uncommon today because most issuers retain grace period as the standard interest-free path.

The OCC’s helpwithmybank.gov balance method explainer summarizes the variants.

Two cycle billing was banned by the CARD Act

Before 2009, some issuers used “two cycle billing” which averaged your balance over the current AND prior billing cycle. This effectively eliminated grace period benefits because the prior cycle’s balance was always pulled into the math.

The Credit Card Accountability Responsibility and Disclosure Act of 2009 (Public Law 111-24) effectively banned two cycle billing for most consumer cards by limiting how issuers could compute finance charges. Today, virtually all U.S. consumer cards use single cycle ADB.

The CFPB CARD Act overview summarizes the law’s impact on balance computation methods, late fees, penalty APRs, and minimum payment disclosures.

Worked ADB calculation

The pillar APR interest calculator computes ADB and finance charge for any combination of starting balance, purchases, and payments. A detailed walk-through:

Cycle setup, 30 day cycle, 22.76 percent APR:

• Day 1 starting balance: $2,500
• Day 8: $1,500 purchase posts (new balance $4,000)
• Day 16: $300 purchase posts (new balance $4,300)
• Day 22: $1,000 payment posts (new balance $3,300)
• Day 30 cycle close: $3,300

Daily balance windows:

ADB = $105,000 / 30 = $3,500.00

Finance charge = ADB times DPR times days

• = $3,500 times 0.0006236 times 30
• = $65.48

The $65.48 posts as one Finance Charge line on the next statement.

Side by side: ADB method vs other balance computation methods

A 30 day cycle, 22.76 percent APR, with the above transactions ($2,500 start, $1,800 in purchases, $1,000 payment, $3,300 close):

The CFPB account-opening disclosure rules require the issuer to clearly state which method applies. The Schumer box on the back of every cardholder agreement names the method explicitly.

Posting date vs transaction date impact on ADB

A purchase made on day 8 but posted on day 11 enters ADB on day 11, not day 8. Three extra days of lower balance. Conversely, a payment made on day 22 but posted on day 24 (because it was made after the 5 PM cutoff) leaves the balance higher for two extra days.

For a $1,000 payment at 22.76 percent APR with two days of posting delay, the additional ADB contribution is ($1,000 times 2) / 30 = $66.67. Finance charge increase: $66.67 times 0.0006236 times 30 = $1.25. Small per cycle, but a recurring pattern of late posting compounds across the year.

The OCC payment cutoff page lists typical cutoff times by major issuer.

Lower ADB by paying earlier in the cycle

Each day of lower balance reduces the daily sum that feeds into ADB. A $1,000 payment moved from day 25 to day 5 of a 30 day cycle reduces ADB by $666.67 ($1,000 times 20 days, divided by 30), saving roughly $12.47 in finance charge for that cycle. Across 12 cycles, that pattern saves roughly $149.64 per year on this single $1,000 payment timing.

The sibling page on mid cycle payments shows the full annualized math.

Avoid losing grace period

The ADB method only matters if you carry a balance. Pay the full statement balance by the due date and the grace period waives all interest entirely. The CFPB’s grace period guide walks through the conditions.

If grace is lost, restoring it requires paying the full statement balance for two consecutive cycles in most issuer policies. American Express restores grace after one full payment on most products.

Check your Schumer box for the exact method

The Schumer box is the table of disclosures on the front of your cardholder agreement under Regulation Z 12 CFR 1026.5a. It includes:

• Annual percentage rate (APR) for purchases
• APR for cash advances
• APR for balance transfers
• Penalty APR and conditions
• Grace period for purchases
• Method of computing the balance for purchases
• Annual fee
• Transaction fees (cash advance, balance transfer, foreign)
• Penalty fees (late, returned payment, over the limit)

The “method of computing the balance” line names ADB (including or excluding new purchases) or whatever variant applies. Read it before applying examples from this page.

Authoritative sources

• Consumer Financial Protection Bureau, How credit card interest is calculated
• Regulation Z, 12 CFR 1026.7(b)(5) (Balance computation method disclosure)
• Regulation Z, 12 CFR 1026.5a (Schumer box requirements)
• CFPB CARD Act report
• Federal Reserve G.19 Consumer Credit
• helpwithmybank.gov, Interest and finance charges (OCC)

Sibling questions

• How is credit card interest calculated?
• Does credit card interest accrue daily or monthly?
• How does daily periodic rate work?
• Does paying mid cycle save interest?

Related tools

• Credit card APR interest calculator computes ADB and finance charge
• Credit card payoff calculator for full payoff math
• Biweekly payment credit card calculator

Frequently asked questions

What is the average daily balance method on a credit card?

The average daily balance (ADB) method sums your ending balance for each day in the billing cycle, then divides by the number of days in the cycle. The result is the ADB. The issuer multiplies ADB by the daily periodic rate, then by days in the cycle, to calculate the finance charge. This is the most common balance computation method in the U.S. and is required to be disclosed under Regulation Z (12 CFR 1026).

Does the average daily balance include new purchases?

On most U.S. credit cards, yes. The method is technically called ‘average daily balance including new purchases.’ Each new purchase increases the daily balance from its posting date forward. A small number of cards use ‘average daily balance excluding new purchases,’ which gives new purchases a one-cycle interest-free runway, but this is uncommon post-CARD Act. Check your Schumer box for the exact method.

How is the average daily balance calculated example?

If your balance is $2,000 for the first 10 days, $5,000 for the next 10 days (after a $3,000 purchase), and $3,000 for the last 10 days (after a $2,000 payment), the ADB equals ($2,000 times 10 + $5,000 times 10 + $3,000 times 10) divided by 30, which equals $3,333.33. Multiplied by a 0.0006236 DPR and 30 days, the finance charge is $62.36.

Is the average daily balance method legal?

Yes, and it is the most common method in the U.S. credit card industry. Regulation Z (12 CFR 1026) requires issuers to disclose the balance computation method in the Schumer box and account-opening disclosures. The CARD Act of 2009 banned the older two cycle billing method (which used a two month average) but left the standard one cycle average daily balance method intact.

What is the difference between average daily balance and previous balance methods?

Previous balance method uses the balance at the END of the prior cycle as the basis for the entire current cycle’s interest, ignoring payments and purchases made during the current cycle. The average daily balance method tracks balance changes daily. ADB is fairer to the consumer because mid cycle payments lower the interest charge. Previous balance is uncommon today but does still exist on some store cards.