CD Calculator by Month

Calculate your certificate of deposit return month by month. Enter your deposit and rate to see a detailed monthly breakdown of interest earned and balance growth across any CD term.

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Your CD Earnings

Final Balance $10,511.62
Total Interest Earned $511.62
Initial Deposit
$10,000.00
Annual Percentage Yield (APY)
5.00%
CD Term
12 months
Compounding Frequency
Monthly

What Is a CD Calculator by Month?

A CD calculator by month breaks down the earnings on a certificate of deposit (CD) into monthly intervals. Instead of showing only the final lump-sum result, a monthly CD calculator reveals how much interest accrues each month and how the balance grows from one month to the next. This month-by-month view helps depositors track progress, plan withdrawals, and compare CDs with different term lengths on a per-month basis.

Deposit & Term
  • Deposit Amount
  • APY Rate
  • Term Length
  • Compounding
Month Tracker A = P × (1 + r/n)n×t
Monthly Schedule
  • Interest Earned
  • Final Balance
  • Growth Chart

Key Benefits of Using a CD Calculator

  • See the exact dollar amount of interest your CD earns in month 1, month 6, month 12, and every month in between
  • Compare the monthly interest income from a 6-month CD versus a 12-month or 24-month CD at the same rate
  • Plan around monthly interest payments on CDs that distribute interest to a linked checking or savings account each month
  • Track how compound interest accelerates from month to month — each month's interest is slightly higher than the previous month

Monthly CD Interest Calculation

The month-by-month CD formula calculates interest for each individual month and tracks the running balance. Each month, interest is computed on the current balance (principal plus all previously earned interest), producing a slightly increasing interest payment each month due to compounding.

= × ( 1 + / ) ×

Click or tap any variable to see what it means

Bₘ Balance After Month m
The running CD balance at the end of month m. This equals the previous month's balance plus that month's interest payment. The balance increases each month as interest compounds.
Iₘ Interest in Month m
The dollar amount of interest earned during month m. Calculated as the balance at the start of the month multiplied by the monthly rate (r ÷ 12).
P Starting Balance
The original deposit amount. This is the balance at the start of month 1. All subsequent months use the compounded running balance.
r Annual Rate
The yearly interest rate as a decimal. Divided by 12 to produce the monthly rate applied to each month's opening balance.
m Month Number
The sequential month within the CD term. Month 1 is the first month after opening. A 12-month CD runs from month 1 through month 12. A 60-month CD runs through month 60.

On a $10,000 CD at 5.00% compounded monthly: month 1 interest = $41.67, month 6 interest = $42.54, month 12 interest = $43.38. Each month earns slightly more because compounding increases the base balance. The total across 12 months = $511.62.

How to Use the CD Calculator by Month

Break down your certificate of deposit earnings into monthly intervals in 3 steps. The calculator shows a month-by-month schedule of interest and balance growth.

1

Enter Your Deposit and Rate

Type the dollar amount of your CD and the annual percentage yield (APY). The calculator divides this rate by 12 to compute the monthly interest applied at the end of each month.

2

Set the Term in Months

Choose the CD term in months for the most precise monthly breakdown. Common terms include 3 months, 6 months, 9 months, 12 months, 18 months, 24 months, 36 months, and 60 months. Set compounding to Monthly.

3

View the Monthly Breakdown

The calculator displays total interest earned, the final balance, and a growth chart showing the month-by-month trajectory. Use the results to plan around specific months — for example, knowing the balance at month 6 helps if you are considering a shorter term.

Factors That Shape Monthly CD Earnings

Four factors determine how much your certificate of deposit earns on a month-by-month basis. Understanding these factors helps you pick the right CD term measured in months.

1

Number of Months in the Term

More months means more compounding events and higher total interest. A $10,000 CD at 5.00% earns $41.67 in month 1 but $511.62 total over 12 months. Extending to 24 months earns $1,044.86 total — more than double the 12-month total because of accelerating compound growth.

2

Monthly Interest Growth Pattern

Each successive month earns slightly more interest than the previous month. On a $10,000 CD at 5.00%, month 1 earns $41.67 and month 12 earns $43.38 — a $1.71 increase from the first to last month. Over a 60-month term, the monthly interest grows from $41.67 to $50.62.

3

Short-Term Monthly CDs (3 to 6 Months)

Short-term CDs of 3 to 6 months produce a smaller total return but keep your money accessible sooner. A $10,000 CD at 5.00% earns $125.52 over 3 months and $252.09 over 6 months. These terms are popular for parking emergency funds or bridging between larger investments.

4

Monthly Interest Payout CDs

Some CDs distribute earned interest to a separate account each month instead of reinvesting it into the CD balance. These payout CDs earn simple interest (not compound) and produce less total return. A $10,000 payout CD at 5.00% pays $41.67 per month for 12 months = $500.00 total, versus $511.62 with compound reinvestment.

Monthly Interest Progression: $10,000 at 5.00% APY (12 Months)

Month-by-month interest earned on a $10,000 CD at 5.00% APY

CD Calculation Examples by Month

These 4 examples show how a certificate of deposit earns interest over different monthly terms. All examples use monthly compounding (12 times per year) to produce a clean month-by-month breakdown.

$7,500 CD — 3 Months at 4.85% (Monthly)

Initial Deposit
$7,500
APY
4.85%
Term
3 Months
Compounding
Monthly (12/yr)
Interest Earned $91.34
Final Balance $7,591.34

$7,500 CD — 18 Months at 4.85% (Monthly)

Initial Deposit
$7,500
APY
4.85%
Term
18 Months
Compounding
Monthly (12/yr)
Interest Earned $556.95
Final Balance $8,056.95

CD Calculator by Month — Frequently Asked Questions

How do I calculate CD interest per month?

Divide the annual rate by 12 to get the monthly rate, then multiply it by your current balance to find each month's interest.

How much interest does a $10,000 CD earn per month?

A $10,000 CD at 5.00% APY compounded monthly earns about $41.67 in month 1, increasing slightly each month due to compounding.

Is a 6-month CD or a 12-month CD a better value?

A 12-month CD earns more total interest than a 6-month CD at the same rate because compounding has more time to work.

Can I receive CD interest monthly without closing the CD?

Yes, some banks offer CDs that pay interest monthly to a linked account, though total returns are slightly lower than reinvesting.