Find out what a single one-off investment could be worth after any number of years, and see how much of that growth arrives in the final stretch.
Step 1
Enter the amount
The single sum you plan to invest today, such as a bonus, maturity payout or accumulated savings.
Step 2
Set an expected return
Use a realistic long-run annual rate for where the money will actually sit.
Step 3
Choose how long you will leave it
The horizon matters more than the amount — watch the curve steepen in the later years.
Future value
$104,431
What your investment could be worth after 15 years.
Amount invested
$25,000
A single payment made at the start, left untouched throughout.
Total gain
$79,431
The final year alone adds $9,494.
A lumpsum grows by simple compound interest. Because nothing is added or removed, the entire result comes from the original amount earning a return on an ever-larger base.
FV = P × (1 + r)ᵗFuture value
What the investment is projected to be worth at the end.
Principal
The one-off amount you invest today.
Annual return rate
The expected return as a decimal. A 12% return gives r = 0.12.
Years invested
How long the money stays invested.
The total gain is FV − P, and the wealth multiple is FV ÷ P. The chart plots monthly points using the equivalent effective monthly rate, (1 + r)^(1/12) − 1, so the curve is smooth while every year-end value still matches P × (1 + r)ᵗ exactly.
Answers about the lumpsum calculator.
Continue exploring adjacent tools in this topic.
Background reading on the ideas behind these numbers.
For most people the question answers itself, because a SIP is simply what investing a salary looks like. The genuine dilemma arrives when a large sum lands at once — and there the arithmetic and the behavioural answer point in different directions.
The arithmetic of long-horizon investing is lopsided: the final decade of a thirty-year plan produces more wealth than the first twenty years combined. Here is why duration beats cleverness, and what that means for when you start.
This tool is provided for educational purposes only. Results are estimates based on the values you enter and do not constitute financial advice.