How to use this calculator
- Choose whether to solve by target date (find the contribution needed) or by contribution (find how long it takes).
- Enter your savings goal and how much you've already saved toward it.
- For 'by target date', enter how many years and months away your goal is. For 'by contribution', enter the amount you plan to save each period.
- Choose how often you contribute, and enter the APY quoted by your bank or credit union.
- Review the contribution or time needed, the chart of your balance approaching the goal line, and the yearly schedule. Share the link or export the schedule as CSV.
How it's calculated
Your balance grows using the same compound-growth math as the compound interest calculator: a lump sum compounds as FV = P × (1 + r)n, and regular contributions grow with the future-value-of-an-annuity formula. Because savings accounts typically compound daily, the APY you enter is converted into the equivalent daily-compounding nominal rate before the projection runs.
By target date: the calculator searches (by bisection) for the smallest periodic contribution whose projected balance reaches your goal by the target date, given your current savings and APY.
By contribution: the calculator projects your balance year by year until it reaches the goal, then estimates the fraction of the final year with straight-line interpolation between that year's start and end balance.
Target dates entered in years and months are converted to an exact number of contribution periods (e.g. 1 year 5 months of monthly contributions is 17 monthly periods) — the solve honors the full target date, including a target under a year away. The chart and yearly schedule still group results by whole year for display.
Assumptions
- The APY you enter is assumed to stay constant for the full term; real savings and CD rates change over time and vary by institution.
- Contributions are assumed to happen exactly on schedule with no missed deposits, fees, or early withdrawals.
- This calculator doesn't recommend or compare specific banks, accounts, or CD terms — enter the APY from any account you're considering to see how it performs.
- Results are estimates for planning purposes only, not a guarantee that any specific account will earn the rate you enter.
Frequently asked questions
What's the difference between APY and APR?
APR (annual percentage rate) is the nominal, stated interest rate before compounding is applied. APY (annual percentage yield) is the effective rate you actually earn in a year after compounding, so it's always equal to or higher than APR for the same account. Savings accounts and CDs are required to advertise APY so you can compare offers on equal footing, which is why this calculator asks for APY directly.
Why does the calculator ask for APY instead of a plain interest rate?
Because APY already reflects how often your bank compounds interest, you don't need to know or enter that compounding frequency yourself. The calculator converts your APY into the equivalent daily-compounding rate internally, matching how most savings accounts and money market accounts actually compound.
What is a high-yield savings account (HYSA)?
A high-yield savings account is a savings account, usually offered online, that pays a meaningfully higher APY than a typical brick-and-mortar bank's savings account while remaining federally insured (FDIC for banks, NCUA for credit unions) up to the standard limits. Funds stay liquid — you can typically withdraw at any time — which makes HYSAs a common home for a savings goal like this one.
What is a CD, and how is it different from a savings account for this goal?
A certificate of deposit (CD) locks in a fixed APY for a set term (e.g. 6 months to 5 years) in exchange for limited access to the money before maturity, usually with an early-withdrawal penalty. CDs can suit a goal with a known date, since the rate won't drop during the term, but you should compare the CD's term to your target date before committing funds.
How is the required contribution calculated?
The calculator tests contribution amounts and projects your balance forward using compound growth until it finds the smallest periodic contribution whose ending balance meets your goal by the target date, given your current savings and the APY you entered. It accounts for interest earned along the way, so as your balance grows, later interest does some of the work for you.
What if I can't reach my goal by my target date?
The calculator will say the goal isn't reachable only when even a very large contribution wouldn't get there in the time available, which is rare. More commonly, you'll just see a larger required contribution than expected; try a later target date, a higher APY account, or a lower goal.
Does it matter whether I contribute monthly, biweekly, or quarterly?
More frequent contributions of the same total annual amount earn slightly more interest, because money reaches your account sooner and has more time to grow. The effect is usually small compared with the impact of APY and time, but the calculator models each frequency exactly so you can compare.
Should I keep my goal savings in a savings account, CD, or something else?
This calculator doesn't recommend specific products. In general, savings you might need on short notice, or before a firm date, are commonly kept somewhere liquid and insured, while money you're confident you won't need before a set date may earn a higher fixed rate in a CD. Compare the APY, liquidity, and insurance coverage of any account before choosing.
Is my money safe in a savings account or CD?
Deposits at FDIC-insured banks and NCUA-insured credit unions are insured up to $250,000 per depositor, per institution, per ownership category. That insurance covers the safety of your deposit — it doesn't guarantee any particular APY, which banks can change on non-CD accounts at any time.
How accurate is the 'time to reach goal' estimate?
The year-by-year balance is calculated exactly for your inputs. The fractional year (months) is estimated with straight-line interpolation within the year your balance crosses the goal, which is a close approximation since growth within a single year is close to linear at typical savings rates.
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Disclaimer: This calculator provides estimates for educational purposes only and is not financial, tax, or legal advice or an offer of credit. Actual payments depend on your lender, loan terms, taxes, and insurance. Consult a qualified professional before making financial decisions.