About

This simulation tool replicates some of the functionality of Karsten (Big Ern) Jeske’s Safe Withdrawal Rate simulation Google Sheet. For more information on this, see Part 28 of Karsten’s SWR Series.

Briefly, the tool uses monthly return data from 1/1871 to 9/2024 to simulate retirements that share your provided parameter values. Retirements starting at the beginning of each month between 1871 and 2015 are simulated, at most. Aggregate statistics for the retirements are then reported. For instance, the proportion of retirements that have less than your provided target at their ends is reported as the failure rate. Part 8 of the SWR Series discusses the underlying math.

The tool is still under construction, and we will add more features over time. If you have questions or suggestions, please get in touch with us at support@saferetirementspending.com.