Guides
The parts of retirement planning that are usually explained badly, explained plainly. Written by the person who built the model, with the assumptions on the table.
How to tell whether you can actually afford to retire
Not a savings target. Three numbers, ten minutes, and why “am I behind?” has no answer as asked.
How much you actually need in retirement
The 80% rule, the 4% rule and 25× spending — what each really claims, and where each breaks.
How much investment risk do you actually need to take?
“What should I invest in?” has no answer until you know what return your plan requires — which is arithmetic.
Claiming Social Security at 62, 67, or 70
77% more a month for waiting, a break-even at 80 — and why the break-even is the wrong question.
Sequence-of-returns risk, and why averages lie
The same ten years of returns, reordered, leave one retiree with twice what the other has.
What a retirement “success probability” actually means
It is a count of simulated futures, not a forecast — and why 95% is not obviously better than 85%.
More are being written. In the meantime, the methodology page covers how the projections work, and can I retire? answers the question for 42 combinations of age and savings.