Finance calculators

Savings Interest Calculator

Updated Jun 26, 2026 By Jehan Wadia
Formulas
Deposits & Contributions
Initial lump-sum deposit. Negative values allowed.
Recurring deposit each month. Slider $0–$5,000; type any value (incl. negative).
Lump sum added at the end of each year. Runs alongside monthly deposits.
Interest & Compounding
With annual compounding this is treated as APY; otherwise as a nominal annual rate compounded at the chosen frequency.
Interest is compounded monthly (12×/year).
Time Frame & Tax
Time Frame (Years)
Reduces net interest only. Default 0%.

Results Summary

End Balance
$0.00
Starting Amount
$0.00
Total Contributions
$0.00
Total Interest Earned
$0.00

Contributions are assumed to be made at the end of each period.

Step-by-Step Solution
Balance Composition
Balance Growth Over Time
Accumulation Schedule
Period-by-period accumulation schedule showing deposits, interest earned, and ending balance.
Period Deposit Interest Earned Ending Balance

Interest values are shown net of tax when a tax rate is set.


Introduction

This savings interest calculator shows you how much your money can grow over time. Enter your starting balance, monthly deposits, interest rate, and how long you plan to save. The tool does the math for you and shows your total interest earned, final balance, and a full breakdown by month or year.

You can choose how often your interest compounds — daily, monthly, quarterly, or even continuously. If you increase your contributions each year, the calculator handles that too. You can also add a tax rate to see how taxes reduce your interest earnings.

Use this calculator to compare savings accounts, plan for a goal, or simply see the power of compound interest. Results update instantly with charts, a step-by-step solution, and a detailed accumulation schedule so you know exactly where your money goes.

How to Use Our Savings Interest Calculator

Enter your savings details below to see how your money grows over time. The calculator will show your end balance, total interest earned, a step-by-step breakdown, and charts that track your growth year by year.

Starting Amount: Type the amount of money you already have saved. This is the lump sum you begin with. You can enter zero if you are starting from scratch.

Monthly Contribution: Enter how much money you plan to add each month. Use the slider or type any amount. Enter zero if you will not make monthly deposits.

Monthly Contribution Growth Rate: Enter a percentage if you plan to increase your monthly deposit each year. For example, entering 5 means your monthly deposit goes up by 5% at the start of each new year. Leave this at zero if your monthly deposit stays the same.

Annual Contribution: Enter a lump sum you plan to add once per year on top of your monthly deposits. Leave this at zero if you do not make a yearly deposit.

Annual Contribution Growth Rate: Enter a percentage if you plan to raise your yearly deposit each year. Leave this at zero if your yearly deposit stays the same.

Annual Interest Rate: Enter the interest rate your savings account pays per year. Use the slider or type in any rate. For example, enter 5 for a 5% annual rate. If your bank advertises an APY instead of a nominal rate, you can use our APY calculator to understand how those figures compare.

Compounding Frequency: Pick how often your bank adds interest to your balance. Most savings accounts use daily or monthly compounding. If you are not sure, choose monthly. To explore how daily compounding specifically affects your returns, try our dedicated tool.

Time Frame: Choose whether to enter your time in years or months, then type the number. This is how long you plan to save. Use the slider or type any value up to 50 years or 600 months.

Tax Rate on Interest: Enter the tax rate that applies to your interest earnings. This only affects the interest you earn, not your deposits. Leave this at zero if you do not want to factor in taxes. If you need help figuring out your bracket, try our tax bracket calculator.

Press the Calculate button to see your results. Press Reset to clear all fields and start over.

What Is a Savings Interest Calculator?

A savings interest calculator shows you how much money you will have in the future when you save and earn interest over time. You enter your starting deposit, how much you add each month or year, your interest rate, and how long you plan to save. The calculator does all the math and gives you a clear answer. If you want to project the growth of a lump sum without regular deposits, our future value calculator is another helpful option.

How Savings Interest Works

When you put money in a savings account, the bank pays you interest. Interest is extra money the bank gives you for keeping your money with them. The amount you earn depends on your interest rate, which is shown as a percentage. If you need to compare rates across different products, our interest rate calculator can help.

The real power of saving comes from compound interest. This means you earn interest not just on the money you put in, but also on the interest you already earned. Over time, your money grows faster and faster because each round of interest is bigger than the last. This is sometimes called "earning interest on your interest." A quick way to estimate how fast your money doubles is the Rule of 72 calculator.

What Is Compounding Frequency?

Compounding frequency is how often the bank adds interest to your balance. It can happen once a year (annually), once a month (monthly), once a day (daily), or even continuously. The more often interest compounds, the more you earn. Most savings accounts compound daily or monthly. If you are comparing a high-yield savings account specifically, our HYSA calculator is tailored for that purpose, and for certificates of deposit you can use our CD calculator.

Why Contributions Matter

Adding money to your savings on a regular schedule makes a big difference. Even small monthly deposits grow into large amounts over many years thanks to compound interest. The earlier you start and the more you contribute, the more your savings will grow. You can also set a contribution growth rate to plan for increasing your deposits over time as your income rises. For a broader look at how regular investing builds wealth, try our investment calculator. And if you are saving toward retirement, tools like the retirement calculator, 401k calculator, or Roth IRA calculator can help you set specific targets.

Taxes on Savings Interest

Interest you earn on savings is usually considered taxable income. This calculator lets you enter a tax rate so you can see your true, after-tax earnings. The tax applies only to the interest you earn, not to the money you deposited. To estimate your overall tax liability, you can use our income tax calculator. If you are building a rainy-day fund and want to know the right target, check out our emergency fund calculator. You may also want to factor in inflation to understand your real purchasing power over time.


Formulas used

Periodic Interest Rate
i = \frac{r}{n}
Future Value of Principal (Discrete Compounding)
FV_P = P\,(1 + i)^{N}, \quad N = n \times t
Future Value of Principal (Continuous Compounding)
FV_P = P \cdot e^{r \cdot t}
Monthly Interest Earned (Continuous Compounding)
I_{month} = \text{Balance} \times \left(e^{r/12} - 1\right)
Monthly Interest Earned (Compounding Frequency > 12)
I_{month} = \text{Balance} \times \left(\left(1 + \frac{r}{n}\right)^{n/12} - 1\right)
Monthly Contribution Growth
PMT_m(k) = PMT_m \times \left(1 + \frac{g_m}{100}\right)^{k-1}
Net Interest After Tax
I_{net} = I_{gross} \times \left(1 - \frac{\text{Tax Rate}}{100}\right)
End Balance
\text{End Balance} = P + C + I_{net}

Frequently asked questions

What is the difference between APY and nominal interest rate?

APY (Annual Percentage Yield) includes the effect of compounding within the year. A nominal rate does not. For example, a 5% nominal rate compounded monthly gives an APY of about 5.12%. In this calculator, if you pick annual compounding, the rate is treated as APY. For all other frequencies, it is treated as a nominal rate.

When are contributions added in the calculation?

All contributions are added at the end of each period. Monthly deposits go in at the end of each month. Annual deposits go in at the end of each year. This means your very first deposit does not earn interest until the next compounding period.

Can I enter negative values for contributions?

Yes. A negative monthly or annual contribution means you are withdrawing money from your savings each period. This lets you model scenarios where you spend down your balance over time.

What does the monthly contribution growth rate do?

It increases your monthly deposit by a set percentage at the start of each new year. For example, if you deposit $200 per month with a 5% growth rate, your deposit becomes $210 per month in year 2, $220.50 in year 3, and so on.

What does continuous compounding mean?

Continuous compounding means interest is added to your balance at every possible instant, not just once a day or month. It uses the math formula A = P × e^(r×t). It gives slightly more interest than daily compounding but the difference is very small.

How does the tax rate affect my results?

The tax rate is applied only to the interest you earn, not to your deposits or starting amount. For example, if you earn $1,000 in interest and set a 25% tax rate, your net interest is $750. Your deposits are not reduced.

What is the maximum time frame I can enter?

You can enter up to 50 years or 600 months. If you type a number larger than 600 months, the calculator caps it at 600 months automatically.

Can I use this calculator for a high-yield savings account?

Yes. Just enter the interest rate and compounding frequency your high-yield savings account offers. Most high-yield accounts compound daily, so select Daily from the compounding dropdown.

What is the difference between yearly and monthly view in the schedule table?

The yearly view shows one row per year with total deposits and interest for that year. The monthly view shows every single month so you can see exactly when each deposit and interest payment happens.

Does this calculator account for inflation?

No. All results are shown in today's dollars. The calculator does not adjust for inflation. To understand how inflation reduces your purchasing power over time, you would need to subtract the inflation rate from your interest rate as a rough estimate.

What does the donut chart show?

The donut chart breaks your final balance into three parts: your starting amount, your total contributions, and your total interest earned. Each slice shows a dollar amount and a percentage of the whole balance.

Why does my end balance say zero before I click Calculate?

The calculator runs automatically when the page loads with default values. If all your inputs are zero, the end balance will show $0.00. Enter your numbers and press Calculate or just change any input to see updated results.

Can I use this calculator for a CD or money market account?

Yes. Enter the interest rate and pick the correct compounding frequency. For a CD, you would usually set the monthly contribution to $0 since most CDs do not allow extra deposits after the initial one.

What happens if my balance goes negative?

If withdrawals (negative contributions) exceed your balance and interest, the balance will go negative. The calculator will still show results, but a negative balance means you have taken out more money than you put in and earned.

How accurate are the results?

The calculator uses standard compound interest formulas and is accurate for planning purposes. Actual bank results may differ slightly due to rounding, fee structures, variable rates, or the exact day interest posts to your account.