How to Calculate VOO Returns

The VOO return formula

At its core, estimating investment growth uses the compound growth formula:

FV = P × (1 + r/n)^(n × t)

where P is your starting amount, r is the assumed annual return, n is how many times per year the return compounds, and t is the number of years. Our calculator uses monthly compounding, so n = 12.

Compound growth

Compound growth means that gains from earlier periods are assumed to stay invested and generate their own gains in later periods. Over long time horizons, this can make a large difference in the projected outcome compared to simple, non-compounding growth — which is one reason time horizon matters so much in these calculations.

Contributions

When you add a regular monthly contribution, each contribution is projected forward from the month it's made to the end of your time horizon, using the same compounding assumption. The formula for the future value of a series of equal contributions is:

FV = PMT × [((1 + r/n)^(n × t) − 1) / (r/n)]

where PMT is the contribution amount per period. Your total projected future value is the sum of the future value of your initial investment and the future value of your contributions.

Dividend reinvestment

VOO distributes dividends from the underlying companies in the S&P 500. If those dividends are reinvested, they can meaningfully affect total return over long periods, separately from price appreciation. Version 1 of this calculator does not separately model VOO's actual dividend history or automatic reinvestment — your assumed annual return is a single all-in growth figure. Modeling historical dividend reinvestment explicitly is planned for a future update.

Projected vs. historical returns

It's important to distinguish between a projection and a historical return. A projection, like the one this calculator produces, applies an assumption you choose to future years that haven't happened yet. A historical return describes what actually happened over a specific past period, and it will not exactly repeat in the future. Neither this calculator nor any other tool can tell you what VOO will actually return going forward.