High-yield savings account or CD?
A high-yield savings account and a certificate of deposit (CD) are both insured deposit products that pay interest, but they work differently. A savings account lets you add or withdraw money at any time, and the bank can change its rate whenever it wants. A CD locks your money for a set term, such as 6, 12 or 60 months, and the rate is fixed for that term. If you take the money out early, you usually pay a penalty.
This calculator puts the two side by side. Enter a starting deposit, an optional monthly deposit, the APY of the savings account, and the APY, term and early-withdrawal penalty of the CD. It shows the ending balance and the interest earned for each option over the period you choose, the interest per day and per month, and how long you would need to keep a CD before cashing it in early beats the savings account.
APY vs APR
APY (annual percentage yield) is what a deposit really earns over a year, with compounding included. APR (annual percentage rate), or the plain "interest rate", is the yearly rate before compounding. If a savings account pays 4.00% compounded daily, its APY is about 4.08%. Under Regulation DD (Truth in Savings), banks must disclose the APY on deposit accounts so that you can compare offers on the same footing. When two accounts are quoted differently, convert them to APY first. The calculator also shows each rate as an APR with daily compounding.
How the numbers are worked out
The balance after a number of months is the deposit times (1 + APY) raised to months divided by 12. A monthly deposit is added at the end of each month and earns the savings APY. A CD accepts one deposit, so in this calculator any monthly deposit goes to the savings account in both cases, and it does not change which option wins.
- Period longer than the CD term: the CD matures, and the money is assumed to earn the savings APY for the rest of the period. The calculator does not guess what a new CD would pay.
- Period shorter than the CD term: the CD is cashed in early. The penalty is counted as months of simple interest at the CD APY on the balance withdrawn, and it is not capped, so a large penalty can cut into your deposit. Many bank agreements allow that, so read yours.
- Tax: enter your marginal tax rate to see the interest after tax. The IRS treats interest from savings accounts and CDs as taxable income in the year it becomes available to you, and your bank sends Form 1099-INT when the interest is $10 or more. A penalty for early withdrawal can generally be deducted, and the calculator assumes that.
Interest per day and per month
People often look up "daily interest" to see what an account pays. For a starting deposit, the daily interest is the deposit times ((1 + APY)1/365 − 1). At 4.00% APY, $10,000 earns about $1.07 on day one and about $32.74 in the first month, and interest grows a little each day because it compounds. The calculator shows these figures for both accounts.
What the national averages look like
The FDIC publishes national rates every month. In its release dated September 21, 2026, the national average savings rate was 0.37%, the 12-month CD rate was 1.73% and the 60-month CD rate was 1.38%. The FDIC defines the national rate as the average rate paid by insured banks and credit unions, weighted by their share of domestic deposits. It also publishes a "rate cap" for institutions that are less than well capitalized, which is a limit on what those banks may offer rather than a typical rate. Many online banks pay more than the national average, but rates change and are never guaranteed. This page keeps the FDIC figures as a dated reference, not a live feed.
Deposit insurance
FDIC insurance covers up to $250,000 per depositor, per insured bank, for each ownership category, such as single accounts, joint accounts and certain retirement accounts. The National Credit Union Administration (NCUA) gives the same standard amount per share owner, per insured credit union, for each ownership category. Money in savings accounts and CDs at the same bank counts together toward the limit, so a larger balance can be spread across banks or ownership categories. Check that the institution is insured, for example with the FDIC bank lookup.
Other things to weigh
This is general information, not advice for your situation. A CD can make sense when you know you will not need the money before it matures and you want to lock in a rate. A savings account suits money you may need soon, such as an emergency fund. Look at the CD calculator for the interest of one CD at different terms, and the compound interest calculator for longer-term growth. Also check fees, minimum balances and whether a CD renews automatically.
Frequently asked questions
Is a high-yield savings account better than a CD?
Neither is better for everyone. A savings account keeps your money available and its rate can rise or fall. A CD fixes the rate for its term but charges a penalty if you withdraw early. Enter both APYs in the calculator to see the difference in dollars over your period.
How much interest will I earn per day on savings?
Multiply your balance by ((1 + APY)^(1/365) − 1). At 4.00% APY, $10,000 earns about $1.07 per day at first. The calculator shows interest per day, per month and for the first year for both accounts.
Are savings accounts and CDs insured?
At an FDIC-insured bank, deposits are insured up to $250,000 per depositor, per insured bank, for each ownership category. NCUA-insured credit unions offer the same standard amount per share owner, per institution, for each ownership category.
Official sources
Checked on October 17, 2026: FDIC, National Rates and Rate Caps (information as of September 21, 2026), FDIC, deposit insurance, NCUA, share insurance coverage, IRS, Topic No. 403, Interest received, IRS, Publication 550 and CFPB, Regulation DD (Truth in Savings).
This page gives general information and arithmetic, not financial, tax or investment advice. Rates change, and your own result depends on your bank's terms.