Cost of Waiting Calculator

Most people who delay investing don’t think of themselves as losing money. They think of it as waiting. There’s a plan: start next year, when things are more stable, when income is higher, when the market looks better. The delay feels neutral. It isn’t.

Every year you wait is a year your money could have been compounding. But the loss isn’t just the missed contributions — it’s the compounding on those contributions, and the compounding on that compounding, for every year that follows. Early contributions don’t just grow. They grow on their growth, for decades. Remove them from the equation and you don’t just lose what they were worth. You lose the entire tower that would have grown on top of them.

At $500/month and a 7% return, a 5-year delay over a 30-year horizon doesn’t cost $30,000 in missed contributions. It costs roughly $187,000 — more than six times what you would have contributed in those five years. That’s what forfeited compounding looks like at the end of a long time horizon.

Compound growth is not linear. It follows a J-curve — nearly flat in the early years, then increasingly steep as the balance grows. This shape is why people underestimate the early years: nothing dramatic appears to be happening. The balance isn’t doubling. The contributions feel small relative to the eventual goal.

But that early period is the most important. Each dollar invested in year one has the longest compounding runway of any dollar you’ll ever put in. At 7%, a dollar invested today is worth roughly $7.61 in thirty years. A dollar invested in five years is worth $5.43. The same dollar, invested five years later, is worth 29% less at the end. That gap multiplied across hundreds of monthly contributions becomes the six-figure cost of waiting shown in the calculator above.

The dramatic growth you see at years 20 and 30 — the steep part of the J-curve — only exists because of the foundation built in years 1 through 10. Delay the start and you don’t just lose the early contributions. You cut the roots of the exponential tree.

No. But the question is a trap.

The relevant comparison is never “am I too late versus some ideal starting age.” It’s always “what does starting today cost versus starting one year from now.” That comparison is always the same: starting today wins. The math doesn’t care about your age. It cares about the number of compounding periods.

Consider a 40-year-old with 25 years to retirement. At $500/month and 7%, they end up with roughly $382,000. If they wait just 5 more years — until 45, with 20 years to go — they end up with roughly $247,000. A $135,000 penalty for 5 years of inaction, at a stage of life when people most often tell themselves they’ll “get serious about it later.”

Older investors often have a powerful offset available: higher income and the ability to contribute more. A 45-year-old who can invest $1,000/month instead of $500 partially compensates for lost time. But more contributions can never fully replace more time — because time is the input that creates the compounding runway, and that runway cannot be extended by spending more money.

Start wherever you are. The only meaningful choice is between starting now and starting later — and later always costs more than now.

The barrier isn’t knowledge. Most people who find this calculator already know they should be investing. The barrier is starting — and the most effective way to start is to make the decision once and automate it so it never requires a decision again.

• 1Open a tax-advantaged account if you don't have one — a Roth IRA, traditional IRA, or 401(k) through your employer. The tax benefits compound alongside the returns, making them more valuable than a standard brokerage account for most people.
• 2Set up an automatic monthly transfer on a specific date. A scheduled transfer removes the decision — and the friction — from the process. You stop thinking about whether to invest this month and it simply happens.
• 3Invest in a broad low-cost index fund. A total market fund or S&P 500 index fund captures the long-term return of the market without the risk of picking individual stocks. The 7% default in this calculator reflects what such funds have returned historically.
• 4Start with whatever amount you can afford today. Even $100/month invested now is worth more than $500/month invested two years from now. The compounding clock starts when you start, not when you're ready.
• 5Increase your contribution whenever your income increases. One practical rule: redirect half of every raise to investing. Your lifestyle doesn't need to expand with every paycheck.

The single most common investment mistake isn’t picking the wrong fund, paying too high a fee, or mis-timing the market. It’s waiting to start — waiting for the right amount, the right moment, the right market conditions. Those conditions never arrive, because they’re not the real barrier. The real barrier is the decision to start. Make it once. Make it today.