When can you stop working?

The method5,000 futures

1. Everything is in today's money. Your spending, pay and pots are what they'd buy now, so a number at 70 means the same as a number today.
2. Each future draws a year of shares, bonds, savings rates and inflation at a time. They move together the way they tend to, and extreme years turn up a little more often than a bell curve would allow (fat tails).
3. Investments are rebalanced to your mix every year. Cash in savings and current accounts stays at today's amounts. Pay goes in, spending comes out, and guaranteed pensions arrive when they start.
4. Pension pots are locked until you can touch them. Running out of everything else before then counts as running out. Money taken from them is taxed at your rate.
5. Short of money, I sell taxable investments first (tax on the gain share, and inflation counts as gain), then tax-free accounts, then cash, then pensions. Savings fill your tax-free allowance first. Rates are yours to set, so it works wherever you live.
6. A home's value follows house prices. What you own of it counts in your worth, but it's only money to live on once you sell, so it never stops the money running out.
7. For every age you could stop, I count the futures where the money lasts until you're 95. Your age is the youngest one that clears 90%. With 5,000 futures that's good to about a year either way.
8. No withdrawal rule of thumb. Retirement spending is simulated year by year, in every future.

What basic mode assumesyearly, after inflation

1. Shares return 4% a year compounded, swinging about 16%.
2. Bonds 1.5%, swinging 6%. Savings accounts 0.5%.
3. Home prices 1% a year, swinging about 8%.
4. A current account earns nothing, so it loses inflation: 2.5% a year on average, and sticky when it surprises.
5. Fund fees 0.3%. Pay keeps pace with inflation and no more, because your spending is held flat too.
6. Money lasts until you're 95, in 90% of futures. Both are on the careful side: a 95-year plan and a 9-in-10 bar stack up.