Savings Calculator

How to use this calculator

1. Enter your initial deposit — the balance the account starts with.
2. Add an annual contribution, a monthly contribution, or both. Beside each is an increase, the percent that contribution rises each year; leave it blank for a flat amount.
3. Set the interest rate and how often it compounds.
4. Enter the years to save, and a tax rate if the interest is taxable.
5. Press Calculate to see the end balance, what it is made of, and the year-by-year or month-by-month accumulation schedule.

Switch to Reach a savings goal to ask the question the other way round: name a target and the calculator solves for the flat monthly contribution that gets you there, using the same deposit, rate, compounding, term and tax you entered.

How the projection works

Interest accrues on the money actually in the account, at the rate the chosen compounding frequency implies. Contributions are made at the end of each period: a monthly contribution lands after that month's interest, an annual one after the twelfth month's. Neither earns interest in the period that created it, which is why the first year's interest is calculated on your initial deposit alone.

Tax is charged on interest as it is earned, so what gets credited each period is the after-tax amount. That keeps the results honest in one specific way: the end balance is always exactly your initial deposit plus total contributions plus interest earned, with no rounding gap and nothing unaccounted for.

A worked example

Start with $20,000, contribute $5,000 a year rising 3% annually, at 3% interest compounded annually for 10 years. The end balance is $92,116.99: the $20,000 you started with, $57,319.40 of contributions and $14,797.59 of interest.

The first year shows the end-of-period rule plainly. Interest is $600 — three percent of the $20,000 opening balance, not of the $25,000 that has been paid in by the time the year closes — so the year ends at $25,600. In year two, interest is charged on that $25,600 and the contribution has grown to $5,150.

What each field changes

• Contribution increases. Dropping the 3% annual increase from the example above, so the contribution stays at $5,000, ends the ten years at $84,197.72 instead of $92,116.99 — the rising contribution is worth nearly $8,000.
• Compounding frequency. Switching that same plan from annually to daily raises the end balance to $92,364.84. More frequent compounding always earns more at the same nominal rate, but the gap is modest — about $248 over a decade.
• Tax rate. A 25% tax rate leaves $10,767.06 of interest rather than $14,797.59. Only $3,589.02 of that $4,030.53 difference is tax actually paid; the rest is the growth the tax would have gone on to earn.

Projecting a monthly habit

Save $500 a month in an account earning 4% compounded monthly for 5 years, starting from zero. You finish with $33,149.49 — $30,000 of contributions plus $3,149.49 of interest. Push the same habit to 10 years and the balance reaches $73,624.90: the contributions double to $60,000, but the interest more than quadruples to $13,624.90, because each dollar has longer to compound.

How much should you save?

Two rules of thumb make a plan concrete. The 50/30/20 rule puts about 50% of take-home pay toward needs, 30% toward wants and 20% toward saving and debt. And an emergency fund of three to six months of essential expenses comes first, in an accessible account, before longer-term investing — it is what keeps a surprise bill from turning into debt.

Choosing a realistic rate

Use a rate that matches where the money will actually sit. A high-yield savings account might return roughly 3–5%, while long-term investments have historically returned more with more risk and more year-to-year swings. Cash you may need within a year or two belongs in a safe, accessible account; only money you can leave untouched for years suits higher-return, higher-volatility investments.

Tips and limitations

• Automate it. A fixed transfer on payday is the single most reliable savings habit — you never have to decide to save.
• One steady rate. The projection holds the interest rate constant for the whole term. Real savings rates move, so revisit it as yours changes.
• Whole years. Terms are whole years, up to 100.
• Nominal dollars. Results are not adjusted for inflation, so real buying power grows more slowly than the balance suggests.
• Tax is a single flat rate. Real tax treatment depends on the account and your jurisdiction; tax-advantaged accounts may owe nothing at all.

To model longer-term, higher-return investing with a contributions-versus-earnings split, see the investment calculator; to explore how compounding frequency changes growth on a single sum, use the compound interest calculator. This is general educational information, not financial advice.