Savings Calculator

How to use this savings calculator

What this calculator does. It estimates how a starting balance can grow when a stated nominal annual rate is compounded and regular deposits are added. It is useful for setting a savings target, comparing account rates, testing a contribution schedule, or checking how deposit timing changes a plan. It does not predict future bank rates, taxes, fees, inflation, withdrawals, or whether a particular account is appropriate for you.

When to use it. Use it when planning an emergency fund, a down payment, tuition, a large purchase, or a general cash reserve. It is also useful for comparing two savings accounts with different compounding frequencies or for seeing whether a higher monthly contribution matters more than a small rate change.

How to calculate. The calculator opens with a complete demonstration: $1,000 initially, a 1.3% nominal annual rate, six years, monthly compounding, and $100 deposited monthly at the end of each month. The example workbook is available immediately. To make your own projection:

1. Replace each demonstration value with your plan.
2. Choose the account's compounding frequency and your deposit frequency.
3. Select whether deposits occur at the beginning or end of each contribution period.
4. Read the final balance, principal, interest, APY, annual chart, and table.
5. Choose Download Excel to save the current assumptions and results. Reset clears the demonstration and results; Excel remains unavailable until a complete valid plan is entered again.

Input guide. Initial savings is a required dollar amount of zero or more, such as $1,000; increasing it raises both principal and future interest. Do not type scientific notation or ambiguous decimal-comma values. Annual nominal interest rate is a required percentage from 0% through 100%, such as 1.3%; it is the quoted rate before compounding, not APY. Time length is a required number of years greater than zero and no more than 100, such as 6; fractional years are accepted. Compound frequency states how often interest is credited – yearly through daily, or continuously. Additional deposit is the required dollar contribution per deposit event, such as $100; enter zero when you do not plan to add funds. Deposit frequency sets how many contributions occur each year, or Never. Deposit timing determines whether each contribution earns interest during its contribution period; beginning-of-period deposits generally produce a slightly higher result.

Output guide. Final savings is the estimated closing balance. Total principal is initial savings plus all scheduled deposits. Total interest earned is final savings minus principal; at a 0% rate it is zero. Annual percentage yield (APY) converts the nominal rate and compounding choice into an effective one-year yield; for continuous compounding it uses the exponential limit. The Balance breakdown separates initial savings, additional deposits, and interest. The Year-by-year projection reports each year's opening balance, deposits, interest, and closing balance. The chart plots the same annual closing balances and is an estimate, not a guarantee.

Worked example. With the startup values, 72 deposits of $100 add $7,200 to the initial $1,000, so total principal is $8,200. Monthly compounding at 1.3% produces an APY of about 1.31%. Deposits made at each month-end and the opening balance accumulate to a displayed final savings value of $8,573.22, including $373.22 of interest.

Learn more. The U.S. Securities and Exchange Commission's compound interest explanation provides useful context for how interest-on-interest affects long-term balances. The Federal Deposit Insurance Corporation explains deposit insurance coverage, while the Consumer Financial Protection Bureau offers guidance on building savings.