Unused knowledge is worthless

Divide 72 by your rate of return and you get roughly how many years it takes to double your money. That single piece of arithmetic is the whole argument for starting now.

Deborah Daniel, CPA

1 Oct 2026 · 5 min read

From episode 4 of Cracking the Wealth Code

A man in an apron wipes down the counter of an empty cafe, looking out of the window.

It is called the Rule of 72, and it is an approximation rather than a formula anyone would use to build a plan. But it is close enough to be useful in your head, which is the point. You do not need a spreadsheet to see the shape of what is happening.

Work it through once

Say you put ten thousand dollars somewhere earning around eight per cent a year. Seventy two divided by eight is nine, so in roughly nine years you have about twenty thousand. Nine years after that, about forty thousand. Nine more and you are near eighty.

Look at what each step added. The first doubling added ten thousand. The last one added forty. Nothing changed about the rate or about what you put in. The growth is compounding on itself, so every doubling is larger than the one before it.

Returns are never a straight line and no rate is promised, so treat eight per cent as an illustration rather than an expectation. The arithmetic still tells you the same thing at four per cent or at ten. Only the length of a step changes.

Why waiting is the expensive part

Most people who are not investing are not refusing to. They are waiting. Waiting for a bonus, for a good quarter, for the debt to clear, for a moment when the amount feels worth bothering with.

The cost of that wait is not the money you did not put in. It is the years you do not get back. Every year you wait removes a year from the far end, and the far end is where the largest doubling would have happened. Ten years of waiting does not cost you ten years of small early growth. It costs you the last, biggest step.

Money needs time the way concrete needs time to cure.

You cannot rush it by pouring more in later. A larger amount with less time in front of it is simply not the same thing as a smaller amount with more.

The best time is the first time you earn anything

The best time to start is the first time you ever earn money. Not when the income is comfortable, not when there is a lump sum. The first paycheque, at whatever size it is.

In practice that might be a small percentage into a workplace retirement plan, enough to collect any employer match on offer, since the match is part of your pay and declining to take it is leaving pay behind. Or it might be a modest automatic transfer on the day money lands, sized so you would not notice it missing.

A small amount starting now genuinely outperforms a much larger amount starting decades later, in most ordinary scenarios. Contribution limits and plan rules are set annually and move, so check the current year's figures before you decide on an amount, but the decision to begin does not depend on knowing them.

Knowing this changes nothing on its own

Here is the uncomfortable part, and it is the reason for the title. Almost everybody reading this already knew, in general terms, that starting early matters. Knowing it has not moved a single dollar.

Unused knowledge is worthless. The gap between the people who end up with assets and the people who do not is almost never information. It is the absence of a structure that acts without them deciding again each month.

A decision you have to make thirty six times over three years is not a decision. It is thirty six chances to skip it, and skipping is easiest in exactly the months when things are tight, which is most of them.

An automatic transfer is not more disciplined than you are. It just does not need to be persuaded on a bad week.

What to do this week

Keep it small enough that you will actually finish it.

Find out whether your workplace plan offers a match and what you have to contribute to receive all of it.
Set one automatic transfer on the day income arrives, at an amount you will not be tempted to reverse.
Put a note in the calendar to raise it slightly the next time your income rises, so the increase is decided now rather than then.
If you are self employed, ask what plan types fit your structure, since the limits and the deadlines differ by type and change from year to year.

Who this is not for

If you are carrying high-cost debt, particularly credit card balances, this is not your first move. The interest you are paying on that debt is very likely higher than any return you could reasonably expect, and it compounds against you on the same arithmetic described above.

In that situation, paying the balance down comes first. The one exception worth considering is contributing just enough to a workplace plan to collect a full employer match, because leaving that behind is declining part of your pay. Beyond that, clear the expensive debt, then start.

It is also not the right frame if your income is genuinely unstable and you have no cash reserve at all. A small buffer comes before a long horizon, because the fastest way to undo years of steady contributions is being forced to pull the money out at the wrong moment.

This is planning, not filing

Which account, in what order, and how it interacts with how you pay yourself is not a question the return answers. That document reports a year that has already happened. The choices that matter here are made while the year is still in front of you. Your Charter team works with business owners on that during the year.

Where this goes next