11 Month CD Calculator

What an 11 month CD is and why the odd length exists

An 11 month certificate of deposit is what the industry calls an off-tenor product: its maturity does not land on the 3, 6, 12, or 24 month marks that most rate sheets print. Banks use odd lengths to compete for cash without disturbing the pricing on their standard cards, and savers use them when a known expense arrives a month before the one year point. Offerings shift with the funding environment, so the first step is to confirm the institution in front of you sells an 11 month length at all.

The FDIC publishes national averages only for on-tenor maturities, and there is no 11 month line in the monthly survey. As of October 19, 2026, the nearest published neighbors were 1.39 percent for a 6 month CD and 1.76 percent for a 12 month CD, according to the FDIC monthly rate survey (October 2026). The rate cap rule itself treats off-tenor lengths as a recognized category: an institution offering a 26 month certificate, for instance, must set its cap from the next lower on-tenor maturity, the 24 month rate.

That missing benchmark is what separates shopping for 11 months from shopping for 12. No published yardstick exists to beat, so an offer has to be judged against the 12 month number, the 6 month number, and whatever the institution pays on nearby lengths. An 11 month APY that sits below the same institution's 12 month rate is a poor trade, because you would surrender a month of access and get nothing in return.

How the 11 month calculator works

The amount at maturity follows the compound interest formula A = P(1 + APY)^t, with t equal to 11 divided by 12 because the length is eleven twelfths of a year. Enter the APY the bank advertises, not the nominal rate: Regulation DD, 12 CFR part 1030 (eCFR, 2026), the federal truth-in-savings rule, requires the APY to fold in the compounding schedule, so the maturity line comes out the same whether interest is posted every day, every month, or once at the end. What changes with the pattern is the nominal rate and the size of each posting, and the calculator reports both.

The early exit side uses the contract equation that dominates US disclosures: penalty = sum × nominal rate ÷ 12 × penalty months. On a 30,000 dollar CD at 4.30 percent APY with interest credited monthly, the nominal rate works out to 4.22 percent, so a 3 month penalty costs 30000 × 0.0422 ÷ 12 × 3, which is $316.31. Interest accrues on the same curve as the maturity amount: by month 7 the total has reached $30,745.89, of which $745.89 is earned interest.

Assembled: the CD matures at $31,180.41 with $1,180.41 of total interest. Close in month 7 and the $316.31 charge leaves proceeds of $30,429.58. You keep $429.58 of the $1,180.41 and hand back $750.83, which is 63.6 percent of what the full length would have paid. The charge is fully covered once three months of interest have accrued, so month 3 is the break-even in this scenario.

The last column never moves because a fixed APY already contains the compounding effect. The credit column is where the pattern shows up: posting every day pays a few dollars at a time, posting once a year pays $1,290.00 in one lump near the end.

Where the 11 month rung sits in a CD ladder

A ladder splits one sum across several CDs that mature on a staggered calendar, so a portion comes back at short intervals. Typical rungs are 3, 6, 12, 24, and 60 months, and the gap between the 6 month rung and the 1 year rung is where an 11 month certificate earns its keep. When it matures in month 11 you still hold the untouched 12 month rung, and the freed cash can be redeployed at the prevailing yield without waiting a full year.

The price of that earlier access is small and computable. One month of interest in the scenario above is $105.44, so an 11 month rung gives up at most about that against an identical 12 month rung, and banks often price odd lengths at the same APY or better to attract the cash. The other side of the trade is reinvestment risk: the 11 month rung forces a rollover decision 30 days before the 12 month rung would. If yields are climbing, the early maturity captures the new higher rate sooner. If yields are sinking, the cash lands in the lower rate one month earlier.

Against the published averages the gap is stark: a competitive 11 month rate pays roughly two and a half times the 12 month national figure for one month less of custody. That is the reward for hunting off the standard shelf. It also explains why banks fold odd lengths into promotional windows: the certificate looks like a bargain next to the printed card, while capping the bank's exposure to eleven months of fixed-rate cash.

Early withdrawal penalties, counted month by month

Federal law sets a floor, not a ceiling: the OCC answer page for bank customers notes that a withdrawal inside the first six days costs at least 7 days of simple interest, and beyond that the disclosure controls the size of the charge. Most contracts on short tenors express it as months of interest, commonly 3 or 6, computed on the sum at the nominal rate. That per month structure makes an 11 month CD easier to reason about than a long certificate, because every month you hold covers exactly one month of charge.

The failure mode appears when the exit comes too soon. Take 40,000 dollars at 4.05 percent APY with interest posted every day and a 6 month charge, closed in month 4. Interest accrued by then is $532.87, but the charge is $794.07, so the bank deducts the difference of 261.20 from principal and returns $39,738.80. Month 6 is the break-even, and any exit before it hands back less than you put in.

Read the rows as a timing map. Any exit before the charge length is covered hands back less than you put in; each month held after that converts one more month of charge into kept interest. In this scenario, closing in month 7 against a 3 month charge keeps $429.58, while a 6 month charge at the same exit would return $30,113.27, barely above the $30,000 you started with.

The liquidity math: what one month of access costs

The honest comparison for an 11 month sum is what the same cash earns in places with no lock. Liquid options in the FDIC monthly rate survey (October 2026) paid under half a percent as of October 19, 2026, which is about $105 on 30,000 dollars across 11 months, against $1,180.41 for the scenario CD at 4.30 percent. The rate gap is the whole argument for accepting a lock at all.

Charges look scarier than they price out. Imagine the exit comes in month 7 against a 3 month length: the $429.58 you keep is more than four times what a typical liquid option would pay for the entire 11 months. Even the harsher 6 month case, which returns $30,113.27 from a month 7 exit, leaves $113.27 of gain, roughly what the average liquid account pays for the whole stretch. The rate gap does the heavy lifting, and the charge only decides how much of it survives.

No-penalty CDs occupy the middle ground: no exit cost, but a lower APY and a shorter menu of lengths. A standard 11 month CD sits at the other end, trading one month of access for a yield the bank sets to compete with 12 month cash. The choice turns on how firm the month 11 date is. If the funds must be there in month 11, the odd length is a feature, not a compromise.

At month 11: what maturity day looks like

An 11 month certificate opened on the 10th of one month reaches its end on the 10th eleven calendar months later, and that date is printed on the disclosure you signed. In the days around it most banks open a grace window, commonly seven to ten days, during which the money can be withdrawn, added to, or moved without any charge at all. Miss the window and the contract usually rolls the whole amount into a fresh certificate of the same length at whatever yield the bank pays that day, which is why the maturity date belongs in a calendar with a reminder set a week early.

Three exits are on the table at maturity. Renewal keeps the relationship but accepts a rate nobody can quote today, and renewal rates are routinely worse than the promotional APY that pulled the money in. A transfer to another institution captures a fresh promotional rate but costs a few days of transit, during which the cash earns nothing or close to it. Spending the sum is the whole point when the month 11 date was chosen for a reason, such as tuition due a month before the one year mark.

There is also a gap cost to weigh while you shop. Parking the matured 31,180.41 in an ordinary account at the 1.76 percent 12 month national average earns roughly $45 for the month it sits there, so a two week hunt for a better rate costs under $25 of interest. That is small next to the $105.44 a month the scenario certificate pays, and it argues for deciding inside the grace window rather than letting the rollover decide for you.

Cover, continuation and taxes before you sign

CDs at FDIC member banks carry protection up to a quarter of a million dollars per person, per institution, the same ceiling the CFPB consumer guide (August 2026) describes. A 40,000 dollar CD sits well inside the limit at a single institution; above that ceiling, coverage rules for different ownership categories can stretch the protection further, and the FDIC deposit insurance (2026) pages explain them.

Watch the continuation clause: most banks extend a certificate past its end date into a fresh like length at whatever yield they pay that day, unless the saver objects during a brief period printed in the disclosure. Mark the date an 11 month CD matures, since an unwatched extension can trap the cash for another 11 months at a stale rate.

Interest is taxed in the year it is posted, whether or not you withdraw it, and the bank reports the amount to the IRS. Before signing, confirm five things in the disclosure: the charge formula, whether the charge can reach principal, the posting pattern, the objection period, and the least you can open with.