Savings Goal Calculator
Quick answer: A $10,000 savings goal with $1,000 already saved, $300 deposited each month, and 4% APY is reached in about 28.3 months — roughly 2 years 4 months — earning about $497 in interest. The exact time-to-goal is n = ln((FV·r + PMT) / (P·r + PMT)) / ln(1 + r), where r is the APY divided by 12. Deposits are assumed at the end of each month and the rate is assumed constant, so treat the result as an estimate.
Set any savings target — a vacation, an emergency fund, a car — and this savings goal calculator tells you exactly when you will reach it. Enter your goal amount, current balance, monthly deposit, and APY to see your timeline in months and years, your projected completion date, total contributions, and interest earned.
Enter your numbers
Your results
Estimate only. Assumes monthly compounding, a constant APY, end-of-month deposits, and no taxes, fees, or withdrawals.
How to use this calculator
Type in the total you want to save, how much you have saved already, how much you can add each month, and the APY your account pays. The calculator updates instantly — tweak any number and watch your timeline change.
The headline result is the time to your goal in months, plus the same timeline in years and months and the calendar date you will finish, counted from today. Below that, the table shows your total contributions and how much of the goal comes from interest.
How this is calculated
The calculator solves the future-value equation FV = P·(1 + r)n + PMT·(((1 + r)n − 1) / r) for the number of months n:
n = ln((FV·r + PMT) / (P·r + PMT)) / ln(1 + r)
- FV = savings goal, P = starting balance, PMT = monthly contribution.
- r = APY ÷ 12 (monthly rate). APY is a nominal annual rate compounded monthly here.
- If the APY is 0, the timeline is simply (goal − starting balance) ÷ monthly contribution.
- Interest earned is computed from the full number of months (rounded up) minus your total contributions.
Assumptions: monthly compounding, deposits made at the end of each month (ordinary annuity), a constant APY, no taxes or fees, and no withdrawals. The result is an estimate, not a guarantee.
Worked example
Inputs: goal $10,000, starting balance $1,000, monthly contribution $300, APY 4%.
Monthly rate r = 0.04 ÷ 12 = 0.003333. n = ln((10,000·0.003333 + 300) / (1,000·0.003333 + 300)) / ln(1.003333) = ln(333.33 / 303.33) / ln(1.003333) ≈ 28.3 months, i.e. about 2 years 4 months. Over 29 full months the interest earned is ≈ $497 (total balance ≈ $10,497 − $9,700 contributed).
Reference data
This tool is pure math and uses no external data tables. The only constants applied are 12 months per year (to convert APY to the monthly rate) and the standard future-value-of-an-annuity formula shown above. No rate figures are assumed — you enter your own APY.
Method & sources
The method is the closed-form solution of the ordinary-annuity future-value equation for the number of periods — the same formula used by finance textbooks for savings timelines. All results are computed live in your browser; nothing here relies on external rates or datasets.
- No external data is used; you supply the APY. All figures labeled (est.) are estimates from the stated assumptions.
Frequently asked questions
How do I calculate how long it takes to reach my savings goal?
Divide your APY by 12 to get the monthly rate r, then solve n = ln((FV·r + PMT) / (P·r + PMT)) / ln(1 + r), where FV is your goal, P is your starting balance, and PMT is your monthly deposit. The calculator on this page solves it for you and converts months into years and months plus a target date.
What happens if my starting balance already covers my goal?
Then the time to goal is zero — you have already reached it. The calculator reports 0 months, total contributions equal to your starting balance, and $0 in earned interest.
Should I raise my monthly deposit or chase a higher interest rate?
Raising the monthly deposit moves the needle more. Each extra dollar deposited each month counts dollar-for-dollar toward the goal, while the interest rate only compounds on the balance already saved, so contribution increases shorten the timeline far more reliably than a slightly higher APY.
Are monthly deposits assumed to be made at the start or end of the month?
At the end of each month. That is the standard ordinary-annuity convention, and it makes this calculator's estimate slightly conservative — if you deposit at the start of each month, you would reach the goal a touch sooner.
Is the result exact or an estimate?
It is an estimate. The math assumes monthly compounding, a constant APY, end-of-month deposits, and no taxes, fees, or withdrawals. Real accounts can vary if the rate changes or you add or remove money unevenly.