How does the ladder split the money?

Evenly, to the cent. $10,000 over five rungs is $2,000 in each, and when the deposit does not divide exactly the leftover cents go on the longest rung, so the shares always add back to what you entered. The first rung matures after the gap you set, the second after twice that, and so on: five rungs 12 months apart run 1, 2, 3, 4 and 5 years.

Where do the rates for each rung come from?

From you. This page has no rate sheet, so every rung starts on the rate in the field above, and typing a figure into a rung's own rate field replaces it for that rung alone. Copy each term's rate off the offer and set the APR or APY toggle to match how the bank printed it, because the toggle applies to every rung.

What does a ladder earn compared with one certificate?

At one rate for every rung, $10,000 over five yearly rungs at 4.5% compounded monthly earns $1,465.58 in total, while the whole $10,000 in a single five-year certificate at the same rate earns $2,517.96. The ladder earns less because most of its money is locked up for shorter terms. What it buys is access: one part comes free each year. With a real rate per rung the gap changes, which is why each rung has a rate field.

Does it work out what happens when a rung matures and is renewed?

No. Renewing a rung means buying a new certificate at whatever rate is offered on that day, and nobody knows that rate today. The table shows each certificate to its own maturity. To estimate a renewal, use the single certificate view with the amount the rung matures at and the rate you expect, and treat the answer as a scenario rather than a forecast.

Can I build a short ladder, like 3, 6, 9 and 12 months?

Yes. Set the rungs to 4 and the months apart to 3. Any whole number of months works for the gap, the ladder can hold 2 to 10 certificates, and the longest rung can run to 600 months.

CD Ladder Calculator

Build a certificate of deposit ladder: enter the whole amount and a rate, choose how many certificates and how many months apart they mature, and the deposit is split evenly across the rungs, to the cent. Each rung shows its share, its value at maturity and its interest, with the totals for the whole ladder underneath. Banks usually quote a different rate for each term, so every rung has its own rate field; one left empty uses the rate above. Nothing is fetched and the arithmetic runs in your browser.

10,000.00 over 5 certificates, 1 year apart, compounded monthly11,465.58Interest 1,465.58 · the last rung matures after 5 years

Deposit

Rate (%)

Quoted as

Rungs

Months apart

Compounding

Ladder value at maturityall 5 certificates added together
11,465.58
Interest earnedon 10,000.00 split across 5 certificates
1,465.58
First rung, one certificate2,000.00 for 1 year, the first to mature
2,091.88

Show

A ladder of certificates

The deposit above is split evenly across the rungs set above, to the cent, and the first rung matures first. Each rung uses the rate above unless you type its own: banks usually quote a different rate for each term, so copy each one off the offer. The APR or APY setting above applies to every rung.

Rung and deposit	Value at maturity	Interest
1 year2,000.00	2,091.88	91.88
2 years2,000.00	2,187.98	187.98
3 years2,000.00	2,288.50	288.50
4 years2,000.00	2,393.63	393.63
5 years2,000.00	2,503.59	503.59
Total10,000.00	11,465.58	1,465.58

Worked examples

Three ladders worked through, one rate on every rung, each one loadable into the fields above. The figures are illustrations of the arithmetic, not rates on offer.

5 certificates, 1 year apart25,000.00 split evenly at 4%, compounded annually
28,164.88 · interest 3,164.88
4 certificates, 3 months apart12,000.00 split evenly at 4.75%, compounded monthly
12,361.95 · interest 361.95
6 certificates, 6 months apart30,000.00 split evenly at 4.25%, compounded daily
32,337.46 · interest 2,337.46

Common questions

How does the ladder split the money?: Evenly, to the cent. $10,000 over five rungs is $2,000 in each, and when the deposit does not divide exactly the leftover cents go on the longest rung, so the shares always add back to what you entered. The first rung matures after the gap you set, the second after twice that, and so on: five rungs 12 months apart run 1, 2, 3, 4 and 5 years.
Where do the rates for each rung come from?: From you. This page has no rate sheet, so every rung starts on the rate in the field above, and typing a figure into a rung's own rate field replaces it for that rung alone. Copy each term's rate off the offer and set the APR or APY toggle to match how the bank printed it, because the toggle applies to every rung.
What does a ladder earn compared with one certificate?: At one rate for every rung, $10,000 over five yearly rungs at 4.5% compounded monthly earns $1,465.58 in total, while the whole $10,000 in a single five-year certificate at the same rate earns $2,517.96. The ladder earns less because most of its money is locked up for shorter terms. What it buys is access: one part comes free each year. With a real rate per rung the gap changes, which is why each rung has a rate field.
Does it work out what happens when a rung matures and is renewed?: No. Renewing a rung means buying a new certificate at whatever rate is offered on that day, and nobody knows that rate today. The table shows each certificate to its own maturity. To estimate a renewal, use the single certificate view with the amount the rung matures at and the rate you expect, and treat the answer as a scenario rather than a forecast.
Can I build a short ladder, like 3, 6, 9 and 12 months?: Yes. Set the rungs to 4 and the months apart to 3. Any whole number of months works for the gap, the ladder can hold 2 to 10 certificates, and the longest rung can run to 600 months.

Exact compound interest arithmetic on the deposit, rate, term and compounding you enter. It cannot know your bank's early withdrawal penalty, fees or tax treatment, and it does not carry any rate of its own.