Savings Calculator
Saving works on two engines: the cash you put in and the compounding that quietly grows what is already there. This calculator runs both at once — starting balance, monthly or annual contribution, interest rate and term — and shows you the full trajectory, including how much of the final number came from deposits and how much from compound interest.
How to project your savings
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1
Enter starting balance
The cash you already have saved. Enter 0 if you are starting fresh.
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2
Set regular contributions
How much you plan to add each month or year, and whether it is made at the start or end of the period.
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3
Pick a rate and compounding
Enter the annual interest rate (APY). Choose whether interest compounds monthly (most common for savings) or annually.
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4
Choose the term
Any number of years. The chart and table update to show balance, contributions paid in and interest earned year by year.
How compound interest actually plays out
Compounding looks modest in year one and spectacular in year thirty. The gap between saving earlier and saving later is not linear — it is exponential.
Future value of 200/month at 6% APY
| Term | Total contributed | Interest earned | Ending balance |
|---|---|---|---|
| 10 years | 24,000 | 8,819 | 32,819 |
| 20 years | 48,000 | 44,398 | 92,398 |
| 30 years | 72,000 | 128,898 | 200,898 |
| 40 years | 96,000 | 297,720 | 393,720 |
Same 200 per month. Same 6% rate. Every added decade more than doubles what the previous one produced.
The core formula
For a series of equal contributions at the end of each period:
FV = P x (1 + r)^n + C x (((1 + r)^n - 1) / r)
Where P = starting balance, C = contribution per period, r = period rate (annual rate / periods per year) and n = total periods.
Practical tips
- Start now, not more. An extra five years at the beginning usually beats adding 50% to your monthly contribution.
- Watch real yield. If inflation runs at 3% and your savings earn 4%, your real return is ~1%. Nominal numbers flatter.
- Rebalance automatically. Monthly contributions smoothed across the year beat a single year-end lump sum in most scenarios.
- Tax-advantaged first. If the account is tax-free (ISA, Roth IRA, TFSA) the compounding compounds even harder.
Frequently Asked Questions
APY already bakes in compounding, APR does not. If a bank quotes 4% APR compounded monthly, the effective APY is about 4.07%. Use APY for savings projections and APR for loans.
Not by default — it shows nominal growth. To see real (inflation-adjusted) growth, subtract expected inflation from your interest rate and enter that net figure.
Start of period (annuity-due) gives you one extra period of compounding, which matters over long horizons. Most employer-matched plans work that way; most manual transfers are closer to end-of-period.
No. The projection is calculated entirely in your browser and the figures you enter never leave your device.
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