Savings & Compound Growth Calculator
Small, consistent saving beats occasional big efforts — because of compounding. See what your money becomes over time.
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How to use the Savings Calculator
Compound growth rewards time and consistency more than big one-off deposits. Enter:
- Starting balance — what you already have set aside.
- Monthly contribution — the amount you can commit every month.
- Expected annual return — use a conservative range; 3–7% after inflation is a common planning assumption, not a promise.
- Years — how long you'll let it grow.
- Target (optional) — a goal balance; the tool shows when you reach it.
Reading your result
Interest earned is the gap between what you put in (contributed) and the final balance — that gap is your reward for starting early. Run the scenario twice, once optimistic and once pessimistic, to see the spread. Small monthly amounts started now usually beat large amounts started late because compounding has more years to run.
Frequently asked questions
Is compound growth really that different from simple saving?
Over 10–20 years, yes. Compound growth reinvests your earnings so you earn returns on your returns. Small monthly amounts started early usually beat large amounts started late because of the extra time compounding runs.
How much should I save each month?
A widely used starting point is 20% of income, split between an emergency fund and longer-term goals. Adjust for your cost of living and country — there is no single global number that fits everyone.
What return should I assume?
Do not assume a fixed high return. Use a conservative range (for example 3–7% after inflation depending on your region and risk) and run the scenario twice — optimistic and pessimistic — to see the spread.
How this savings projection works
This calculator compounds your money monthly, which is how most savings and investment accounts actually behave. Each month your balance grows by one twelfth of your annual return, and your monthly contribution is added on top.
The formula behind it: balance = balance x (1 + r/12) + monthly, repeated once per month for the number of years you choose. Because interest earns interest, the final years of a long horizon usually contribute more than the first ten combined.
A worked example
Start with $1,000, add $300 a month, assume a 7% annual return, and run it for 20 years. You will have contributed $73,000 of your own money; everything above that is growth. Try lowering the return to 4% and raising it to 10% — the gap between those two outcomes over 20 years is larger than most people expect, which is why the return assumption matters more than the contribution amount in the long run.
When to use it — and its limits
- Use it to sanity-check a goal ("can I reach $50,000 in five years?") rather than as a forecast.
- The return rate is an assumption, not a promise. Market returns vary year to year.
- Results are in today's dollars unless you lower the return to account for inflation.
- It does not model taxes, fees, or irregular contributions.