Guyton-Klinger Rules
GK Dynamic Withdrawal Simulator
1Principal & Baseline
Advanced rule parameters
2Annual Market Returns
Bull → Bear
Lost Decade
Crash at Retirement
Steady Growth
All Zero
Each year is editable (negatives shown in red):
Ending balance
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Total withdrawn
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Avg withdrawal rate
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Rule-triggered years
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| Yr | Start balance | CPI draft | Final withdrawal | WR | Market | End balance | Rules |
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Pick a scenario or custom return, then "Run simulation" to see year-by-year results. | |||||||
This tool is for education and scenario exploration, not investment advice. The GK rules were proposed by Jonathan Guyton and William Klinger.
How do the GK dynamic withdrawal rules work?
Guyton-Klinger (GK) is a "dynamic withdrawal" strategy: instead of the rigid 4% rule that adjusts mechanically for inflation each year, it raises or trims the withdrawal based on market performance — aiming to make savings last longer in bear markets while taking a little more in bull markets. Each year's withdrawal is computed in this order:
- Inflation-adjusted draft: last year's withdrawal × (1 + inflation); year 1 = principal × initial withdrawal rate.
- Freeze rule: if last year's market was negative AND the proposed rate exceeds the initial rate, skip the inflation adjustment and keep last year's amount.
- Capital Preservation (CPR): when the withdrawal rate exceeds "initial × trigger ratio", cut by a set percentage to protect principal.
- Prosperity Rule (PR): when the rate falls below "initial × trigger ratio", raise the withdrawal modestly so you enjoy the growth.
FAQ
Q: Does this guarantee my money won't run out?
No. It only models the scenarios you enter; real market returns can't be predicted. Treat it as a "what happens under different scenarios" explorer.
Q: Is my input uploaded anywhere?
No. All calculations run in your browser; we don't collect or store anything you enter.