Methodology
This simulator gives you a realistic, high-level view of how your retirement plan could have performed across many different historical periods. It is designed to be clear and approachable, not overly technical.
We use long-run historical market data for UK, US, and global assets. Each year in the dataset represents how those assets actually performed in the past. This helps us model realistic ups and downs.
Your allocation (stocks, bonds, cash) is used to calculate a single “blended” return for each year. If you choose more stocks, your results will tend to be higher and more volatile. More bonds usually means smoother results.
We don’t rely on just one market period. Instead, we test your plan across many different historical windows to see how it might have held up under a range of conditions.
Spending is adjusted for UK inflation so the buying power stays consistent over time. This keeps the results grounded in real-world costs.
The simulator includes simplified UK tax rules and common account types. This is not personal tax advice, but it helps produce more realistic estimates for UK residents.
The goal is to offer a clear, honest picture of what could happen—not a promise. This tool is best used for planning, comparison, and stress-testing your ideas.
We use multiple academic and market datasets depending on the asset class. The sources below are summarized in plain language: