No crystal balls — just history. Every calculator here replays your plan through 126 years of real market returns, every start year since 1900, and tells you the worst, median and best outcomes in today’s spending power.
Open a pension the day your child is born. See what £10–£300 a month becomes by the time they can draw it — backtested through every market era since 1900.
Financial independence, retire early — UK edition. Tax-aware ISA/SIPP/GIA drawdown with withdrawal strategies, tested against every market since 1900.
Every calculator draws from the same fund series — real funds you can actually buy, extended back to 1900 with documented academic proxies, converted to GBP and deflated with actual UK inflation. Add a fund once, every calculator gets it.