How Long to Save Calculator

Find out how long it will take to reach any savings goal. Enter your target amount, current balance, regular contributions, annual interest rate and how often you pay in. The calculator estimates the time needed, total contributions and interest earned along the way.

This is handy when you know how much you can save each month but want to see when you’ll actually hit your goal.

Inputs
Your target amount (for example, a down payment or emergency fund).
What you already have saved toward this goal.
Amount you plan to add each time you contribute.
How often you add your regular contribution.
%
Expected yearly growth on your savings (can be 0%).
Display only — math is unit-agnostic.
Controls how amounts and percentages are shown.
Estimated time to reach your goal
—

Total contributions

—
Sum of all regular deposits (excluding starting balance).

Interest earned

—
Growth from interest on current and future savings.

Number of contributions

—
How many contributions until you hit the goal.

Final balance (approx.)

—
Goal plus any overshoot from the last full contribution.

Savings journey summary

Enter your goal, current savings, regular contribution and interest rate to see how long it may take to get there.

  • Savings goal: —
  • Current savings: —
  • Interest share of final balance: —

Contributions vs interest

Contributions — 100%
Interest — 0%
Balance over time on the way to your goal
Projected savings balance

How the "how long to save" calculator works

This calculator solves the opposite of a normal savings calculator. Instead of asking how much you’ll have after a certain time, it asks how much time it will take to reach a specific savings goal.

It assumes you:

  • Start with a single current balance.
  • Add the same contribution each period (monthly, weekly, etc.).
  • Earn a steady annual interest rate (which may be 0%).

For a balance with regular contributions and compound interest, the future value after n contributions is: 

FV = P × (1 + r)^n + C × ((1 + r)^n − 1) / r

P = current savings
C = contribution each period
r = periodic interest rate (annual rate ÷ contributions per year)
n = number of contributions

The calculator rearranges this formula to solve for n (the number of contributions needed) and then converts that into years and months based on your chosen contribution frequency.

Step-by-step example: saving for a house deposit

Suppose you want to save $15,000 for a house deposit. You already have $2,000 saved and can add $300 per month. Your savings account pays 4% per year, compounded with each monthly contribution.

  • Savings goal (FV) = 15,000
  • Current savings (P) = 2,000
  • Monthly contribution (C) = 300
  • Annual interest rate = 4%
  • Contribution frequency = monthly (12 per year)

Plugging these into the calculator will show that you can expect to reach your goal in roughly a little over 3 years. The tool also breaks down how much of your final deposit came from your contributions versus interest.

Understanding the result

The headline result is the estimated time to goal. Because contributions are discrete, the calculator rounds up to the next whole contribution – you can’t usually make “half a monthly payment”.

You’ll also see:

  • Total contributions: your initial savings are shown separately so you can see how much new money you put aside.
  • Interest earned: the extra your money grows due to the interest rate.
  • Final balance: your goal plus any small overshoot from the last full contribution.

Why your goal might be unreachable

Sometimes the calculator will report that it can’t find a realistic time to reach your goal. Common reasons include:

  • The goal is lower than or equal to your current savings (you’re already there!).
  • The contribution amount is zero and the interest rate is zero.
  • The interest rate is negative and contributions are too small to catch up.

In these cases, try increasing your contribution, extending the time horizon or adjusting the goal to something more realistic.

Saving faster: levers you can adjust

If the time to goal looks longer than you’d like, there are three main levers you can experiment with in the calculator:

  • Increase your contribution. Even a small bump can shave months or years off the plan.
  • Earn a higher rate. Moving to a better-paying account can help, especially for larger goals.
  • Start with more. Dropping a one-time lump sum into the goal can materially shorten the timeline.

Practical use cases

  • Emergency fund planning. See how long it will take to build three to six months of expenses.
  • Holiday or big purchase. Plan backwards from a travel date or purchase deadline.
  • College or education savings. Combine a starting balance with regular contributions to target a future tuition date.
  • Side-project or business fund. Decide when you’ll have enough saved to comfortably launch.

Frequently asked questions

Does this calculator account for taxes or fees?

No. The interest rate you enter is treated as a net rate after any taxes and fees. If your bank quotes a rate before tax, you may want to adjust it downward to more accurately reflect your real return.

Can the interest rate change over time?

In real life, savings rates can and do change. This calculator assumes a fixed rate for simplicity. If your rate changes, you can re-run the numbers with your new rate and current balance to update the plan.

Is the result guaranteed?

No. The result is a mathematical projection based on your inputs. Actual outcomes depend on your behaviour (whether you stick to the plan) and real-world returns (which may be higher or lower than expected).

What if I want to save by a specific date?

You can reverse the problem: last, calculate how long it will take with your current contribution. Then adjust your contribution upward until the time to goal roughly matches your desired date.