Early vs. Late Start
Time in the market usually beats trying to catch up later
Maya starts investing $400 a month at 25. Dev waits until 35 and invests the same $400, but he keeps going five years longer than she does. Most people assume the person who contributes more cash wins. Run both scenarios and the ranking is often reversed.
Run the two scenarios side by side
Set starting balance to $0, monthly contribution to $400, return to 8%, and years to 40. That is Maya at 25 projecting out to 65. Write the ending number on a sticky note.
Now change years to 30 and leave everything else alone. That is Dev at 35. He is not lazy or careless; he simply lost a decade to student loans and a low-paying first job.
The gap between those two numbers is usually larger than the entire amount Dev will contribute over his 30 years. That is the part that shocks people.
Why the final decade is the loudest one
Compounding is back-loaded. In the first ten years your balance is mostly the cash you deposited, so the line looks almost straight. In the last ten years the balance is mostly growth, and growth earns growth.
That means the decade you cut off is not an average decade. You are deleting the most productive stretch at the end of the curve, not the quiet one at the beginning.
Try it directly: run 40 years, then 35, then 30, and note how much each five-year chunk costs. The chunks are not equal in value.
- $400 a month for 40 years deposits $192,000 of your own cash; the projection ends far above that.
- $400 a month for 30 years deposits $144,000, and ends well below the 40-year run at the same rate.
- Cutting the last ten years costs more than cutting the first ten would.
- Raising the contribution can partly close the gap, but it rarely closes it completely.
What to do if you are the late starter
First, drop the guilt. You cannot invest money you did not have at 22, and regret does not compound in your favor.
Second, find your catch-up number instead of guessing at it. Keep years at 30 and raise the monthly contribution until the ending balance matches the 40-year run. On many input sets that lands somewhere between $650 and $750 a month.
Third, check whether that number fits your real budget. If it does not, extend the timeline by working two or three extra years, or accept a smaller target. A plan you can actually fund beats a spreadsheet fantasy.
The middle path almost everyone should take
You do not have to choose between starting at 25 with $400 and starting at 35 with $700. The version that actually works is starting right now with whatever you can sustain, then raising it as your income grows. A 26-year-old putting in $75 a month has already beaten the 25-year-old who is waiting until the amount feels respectable.
Model that directly. Run $75 a month for five years, then imagine that same person at $250 a month for the following twenty and $500 for the twenty after that. The calculator only handles one constant amount, so approximate it with a blended figure like $300 across the full horizon.
The blended approach is less precise than a spreadsheet, but it answers the only question that matters at the start: is the habit worth beginning before the amount is impressive? The gap between starting now and starting in three years says yes every time.
One honest caveat
This comparison assumes both people earn the same steady 8% every single year, which no real market delivers. The point is not the exact dollar figure — it is the direction and rough size of the gap.
Rerun both scenarios at 6% to see how the story holds up in a more modest market. The early starter still wins, just by less.
Try these inputs
- Early start: $0 balance, $400/mo, 8%, 40 years
- Late start: $0 balance, $400/mo, 8%, 30 years
- Catch-up attempt: $0 balance, $700/mo, 8%, 30 years