Guides: learn the math behind retirement & FIRE
Practical, sourced explainers that show the numbers ??? not just the rules. Each guide links to the relevant calculator so you can test what you learn.
Monte Carlo & simulation
How Monte Carlo Simulation Works (and Its Limits)
Monte Carlo tests thousands of possible return paths for your retirement plan, so you can judge probability — not prediction. Here's how to read the results.
Withdrawal & income
Safe withdrawal rates explained
A safe withdrawal rate (SWR) tells you how much you can spend each year without running out. Here's how it works, its limits, and better approaches.
The bucket strategy, explained with worked numbers
Divide retirement savings into time-based buckets so you spend cash in downturns and let growth ride. Here's a concrete, worked example.
FIRE basics
FIRE retirement: a practical guide
A no-fluff guide to Financial Independence, Retire Early (FIRE) — from savings rate to safe withdrawal rates, with realistic numbers.
FIRE vs traditional retirement: key differences
FIRE aims for financial independence and optional work decades earlier. Traditional retirement focuses on stopping at a fixed age. Here's how they compare.
How to calculate your FIRE number
Your FIRE number is how much you need invested to retire. Here's how to calculate it, stress-test it, and avoid common mistakes.
What is Coast FIRE? (with a worked example)
Coast FIRE means you've saved enough that compound growth can cover the rest — so you can 'coast' to traditional retirement without saving more.
Risk & markets
Sequence of returns risk: why the first few years decide it
Poor returns early in retirement hurt far more than poor returns late. This is sequence-of-returns risk, and it's the biggest reason portfolios fail.
Planning fundamentals
How inflation changes your retirement plan
Inflation quietly erodes purchasing power. Even 3–4% inflation over 30 years cuts real value in half. Here's how to account for it.
How to read a retirement projection (and spot red flags)
A retirement projection shows one possible future. Learn to read the numbers, understand confidence levels, and avoid common traps.
Retirement planning basics: a practical starter guide
Start here if you're new to retirement planning. Learn the key numbers, order of operations, and how to build a robust plan.
The 4% rule vs your assumptions
The 4% rule is a useful benchmark, but it was derived from US history. Here's when it holds, when it breaks, and how to adapt it.