Investment Calculator

Calculate how a one-time investment grows over time. Compare different rates and time periods to see the impact of compound growth.

Your data stays in your browser. Nothing is stored or sent to any server.

Enter Your Details

$0
Future Value (Pre-Tax)
$0
Total Gain
$0
After-Tax Value
$0
Tax on Gains
-- yrs
Doubling Time

How Lump Sum Investing Works

Lump sum investing means putting a large amount of money into the market all at once, rather than spreading it out over time (dollar-cost averaging). Studies consistently show that lump sum investing outperforms dollar-cost averaging about two-thirds of the time because markets tend to go up over the long term.

The Rule of 72

A quick way to estimate how long it takes an investment to double: divide 72 by the annual return rate. At 7% returns, your money doubles in approximately 72 ÷ 7 = 10.3 years. At 10%, it doubles in about 7.2 years.

Tax-Efficient Investing

Long-term capital gains (assets held >1 year) are taxed at 0%, 15%, or 20% depending on your income. Short-term gains are taxed as ordinary income. Tax-advantaged accounts (401k, IRA, Roth IRA) can shield some or all gains from taxes.

Frequently Asked Questions

Is lump sum better than dollar-cost averaging?
Historically, lump sum investing outperforms DCA about 2/3 of the time because markets trend upward. However, DCA reduces the risk of investing at a market peak and can be psychologically easier.
What is the Rule of 72?
Divide 72 by your expected annual return to estimate how many years until your investment doubles. At 8% returns: 72 ÷ 8 = 9 years to double.
How are investment gains taxed?
In the US, long-term capital gains (held >1 year) are taxed at 0%, 15%, or 20%. Short-term gains are taxed as ordinary income. Gains in tax-advantaged accounts grow tax-deferred or tax-free.

Quick Calculator

FC

FinCalcs AI

Financial guidance powered by AI

AI guidance only · Not financial advice