Savings Interest Calculator: See How Much Your Money Can Grow

Enter your savings amount and compare earnings at real bank rates. See the dollar difference between a 0.01% traditional bank and a 4.25% online bank.

Calculator Inputs

$
$

Bank A: Chase Savings

0.01% APY

$22,008

after 5 years

Total contributions$22,000
Interest earned$8

Bank B: Discover

4.25% APY

$25,658

after 5 years

Total contributions$22,000
Interest earned$3,658

By choosing Discover over Chase Savings, you earn

$3,651 more

in interest over 5 years on the same deposits

Year-by-Year Breakdown

YearChase Savings BalanceDiscover BalanceDifference
1$12,401$12,875$474
2$14,802$15,873$1,070
3$17,204$18,999$1,795
4$19,606$22,259$2,653
5$22,008$25,658$3,651

Common Comparisons

Quick reference: annual interest on $10,000 at different banks (no additional contributions).

Chase

0.01% APY

$1

per year on $10,000

Ally

4.00% APY

$400

per year on $10,000

Capital One 360

4.10% APY

$410

per year on $10,000

Discover

4.25% APY

$425

per year on $10,000

How Compounding Works

Daily compounding means the bank calculates interest every day based on your current balance (including previously earned interest). This creates a snowball effect where your earnings accelerate over time.

Example: $10,000 at 4.25% APY with daily compounding earns $11.64 in the first day. On day two, you earn interest on $10,011.64 instead of the original $10,000. After a full year, you have $10,434.03 instead of the $10,425 you would get with simple interest.

Monthly compounding calculates interest once per month instead of daily. The difference is small (a few dollars per year on typical balances), but daily compounding always earns slightly more. Most online savings accounts use daily compounding.

The real power of compounding shows over longer periods and with regular contributions. A $10,000 deposit with $200/month added at 4.25% APY grows to approximately $40,800 after 5 years, of which about $4,800 is interest earned.

Disclaimer: WhatIsTheBestBank.com is an independent comparison guide. We are not affiliated with any bank mentioned on this site. Rates, fees, and terms change frequently. All data was last verified April 2026. Always confirm current details directly with your chosen institution before opening an account.

Calculator FAQ

How is savings interest calculated?
Most online savings accounts use daily compounding. The bank divides your annual APY by 365, applies that daily rate to your balance each day, and adds the interest to your account. Over time, you earn interest on your interest (compound growth). The formula is: A = P(1 + r/n)^(nt) + PMT * [((1 + r/n)^(nt) - 1) / (r/n)], where P is principal, r is annual rate, n is compounding frequency, t is years, and PMT is monthly contribution.
What is the difference between APR and APY?
APR (Annual Percentage Rate) is the base interest rate without compounding. APY (Annual Percentage Yield) includes the effect of compounding and represents your actual annual earnings. For savings accounts with daily compounding, the APY is slightly higher than the APR. Banks are required to advertise savings rates as APY.
How much should I have in savings?
Financial experts generally recommend keeping 3 to 6 months of living expenses in an emergency fund. For a household spending $4,000/month, that means $12,000 to $24,000 in accessible savings. At 4.25% APY, a $20,000 emergency fund earns $850/year instead of $2 at a traditional bank.
Are savings calculator results guaranteed?
No. The calculator shows projected earnings based on a fixed APY. In reality, most savings accounts have variable rates that can change at any time, typically following Federal Reserve decisions. The calculator provides a useful estimate, not a guarantee.