Rolling Returns Calculator

Rolling returns calculate the investment return for a series of overlapping periods rather than a single start-to-finish figure. Instead of asking “what was the return from 2018 to 2024,” rolling analysis asks “what was the compounded return for every 3-year window inside that span”: 2018-2021, then 2019-2022, then 2020-2023, and so on.

For each rolling window, the compounded return:

Compound Return = (1 + r1) x (1 + r2) x (1 + r3) - 1

And the annualized CAGR for any window of N years:

CAGR = [(1 + Total Return)^(1/N)] - 1

Rolling returns expose something a single long-term number hides: sequence risk. Two funds can post identical 10-year CAGRs and have completely different distributions of 3-year windows. The one with a bad early stretch might have wrecked a retiree who started drawing down at the wrong moment, while the headline number for both funds looked the same.

The S&P 500 has produced rolling 10-year periods with negative real returns, 1999 to 2009 being the most recent. It has also produced windows above 15% a year. Knowing the average without knowing the spread gives false confidence, which is why this calculator reports the best window, the worst window, the gap between them, and how many windows finished negative.

Fund managers use exactly this as a consistency metric. A fund that beats its benchmark in 80% of all rolling 3-year windows is a genuinely different product from one that beat it in the single period the marketing brochure happens to quote.

How to enter your data. Put annual returns in as percentages, oldest first in Year 1. The years must be consecutive: a rolling window is only meaningful if the returns inside it actually ran back to back. If you leave a middle year blank the calculator stops at the gap rather than silently compounding across it, because a “3-year window” spanning 2019, 2020 and 2022 is not a 3-year window. With fewer than three consecutive years, only the overall CAGR appears.