Tools and data
Tools and data
Calculators and charts built from public data, so you can test the ideas with your own numbers. Free, no sign-up, and nothing you type is stored.
Everything runs in your browser: nothing you type is sent anywhere or kept. The calculators show the arithmetic behind a decision; the explorers show the data behind a claim. Each page explains how its numbers are worked out and where the data comes from, and links to the guide that covers the idea. The defaults are chosen to be typical rather than flattering, so change them to match your own situation.
Tools
Calculator
Fee calculator: what a fund's fee costs you over time
Compare two yearly fees on the same money and the same growth. The gap is bigger than most people expect.
Interactive
Interactive
Historical returns explorer: UK shares vs cash since 1871
Pick any two years and see what the same money became in UK shares and in cash, before or after inflation.
Interactive
Calculator
Pay the mortgage off fast, or invest the difference?
Two people, same house, same monthly spend. One clears the loan; the other invests the gap. See who retires with more, and when paying it off still wins.
Interactive
Monthly check
ETF trend check: which way have popular ETFs been moving?
Eight trend rules from academic research, applied each month to 18 UK-listed ETFs. It describes the trend. It doesn’t tell you what to do.
Updated monthly
Explorer
S&P 500 ETF explorer: every tracker side by side
Search any S&P 500 ETF listed in London or the US for its 52-week range, returns, risk, costs, holdings and tracking difference.
Interactive
Data guides
Original charts from 150 years of UK data, with the method published alongside.
Worries and myths
Will I lose money investing?
How often UK shares lost money over 1, 5, 10 and 20 years, and how that compares with cash.
2 charts
Worries and myths
What inflation does to cash savings
What £100 could buy from 1970 to 2020 in shares, cash and banknotes.
2 charts
Worries and myths
Every big UK crash since 1871
Eight falls of 20% or more after inflation, and how long each took to recover.
1 chart
Coming next
Each one is built from public data, with the method published alongside it.
- The annual UK ETF cost study