Everything you need to know about SWP Calculator, including how to calculate SWP sustainability, common mistakes, and real-world examples.
SWP Calculator is designed for one primary goal: Withdrawal sustainability and corpus depletion timeline.
By mastering inputs like starting corpus, withdrawal, and expected return, you can deeply model your scenarios to optimize SWP sustainability. In this guide, we break down exactly how it works.
This tool models SWP sustainability for common cases so you can compare tradeoffs quickly.
If your scenario is highly unusual, treat the output as a starting point and validate assumptions before committing.
Unit mismatches (like confusing monthly vs annual inputs) are the #1 error. Label each input before typing it.
If a cost exists in reality (fees, taxes, churn), it must exist in your model inputs. If outputs like ending corpus and depletion estimate look too good, a missing cost is usually the reason.
Key inputs: starting corpus, withdrawal, expected return, and years.
Be consistent about units (monthly vs annual) and scope (include fees/taxes if they exist in real life).
Compare outputs like ending corpus and depletion estimate across scenarios instead of trusting one number.
If the decision changes under downside assumptions, build a buffer or revise the plan.