Cost of waiting to invest calculator, in hindsight

What if I'd started investing earlier?

Pick the year you could have started. This replays real stock market returns and savings rates, starting then or a few years later, to the latest month.

Where
While you waited, the money was
Year you could have started
Your numbers
£e.g.

Loading rates…

 

What each start is worth. The dotted line is what the early start put in. Touch the chart to scrub.

Ctrl Alt Decidectrlaltdecide.com

How it played out

Where the money went

The same monthly amount on both paths; only when the investing started changes.

EarlyLate
How this works

How this cost of waiting to invest calculator works

This calculator replays the cost of waiting to invest with real stock market returns. Pick the year you could have started, any January from 2000, how long you waited, and how much you'd have invested each month. It follows two paths to the latest month: investing every month from the year you picked, or starting the same monthly investing that many years later.

While you waited, the money was either in savings or spent. "In savings" puts the same money in on both paths: the late starter keeps each month's amount in savings at the real rates of the day, then invests the whole pot on the day they start. That shows the cost of waiting alone. "Spent" is the classic comparison: the late starter put nothing away until they began, so they also put in less. Every amount goes in at the end of the month.

Investing follows the S&P 500 with dividends reinvested, month by month, converted to pounds at each month's exchange rate in the UK: a stand-in for a global tracker fund, which is mostly US shares. Savings earn the Bank of England's average one-year fixed-rate bond rate in the UK and the 3-month Treasury bill yield in the US. Everything is tax-free, as in an ISA or a Roth IRA, with no fees.

Worked example

These use the calculator's starting figures for one UK case and one US case, and are refreshed when the data updates.

Had you started investing £200 a month in January 2015 instead of waiting until January 2020 with it in savings, by August 2026 you'd have £14,054 more: £71,448 starting in 2015, against £57,394 starting in 2020.

Had you started investing $300 a month in January 2015 instead of waiting until January 2020 with it in savings, by August 2026 you'd have $18,124 more: $108,661 starting in 2015, against $90,537 starting in 2020.

Where the numbers come from

  • UK: savings rates and exchange rates from the Bank of England. Stock market: S&P 500 with dividends, from Robert J. Shiller's data.
  • US: Treasury bill yields from the Federal Reserve, via FRED. Stock market: S&P 500 with dividends, from Robert J. Shiller's data.

Questions

What does it cost to wait to invest?

It depends on what the market did while you waited, which is why this calculator replays real years rather than assuming a steady return. Pick a start year and a wait above: the big figure is how much more (or less) the early start ended with, and "How it played out" says what the late start would have needed each month to catch up.

What if I had started investing 10 years earlier?

Choose 10 years under "Years you waited" and a start year from 2000 to 2015. With "Spent", the late start also put in ten years less money; with "In savings", both put in the same, so the gap is the cost of the timing alone.

Is it ever better to wait?

Sometimes, over short waits: someone who kept their money in savings through a crash and invested at the bottom could come out ahead. Try starting in 2007 and waiting 2 years. Over longer waits, starting earlier has usually won, because the money spends more years growing.

If I start investing at 25 or 30, how much difference does it make?

Pick "Spent" and a five-year wait: that is the gap between starting at 25 and starting at 30, played out with real returns over the years you choose. The calculator doesn't forecast; for the decades ahead, the past only shows how wide the range can be.