Investing €100/Month: What You'll Have in 10, 20, 30 Years
€100/month seems modest. The stock market at 7% per year turns it into something that surprises most people. Here are the exact projections — with the assumptions clearly stated — so you can make a real decision.
The Base Projections
The scenarios below use 5%, 7%, and 9% annual returns. The MSCI World has returned ~7-8% per year after inflation historically over 50 years — so 7% is our central scenario. 5% is the conservative scenario; 9% is optimistic.
| Duration | Invested | At 5%/yr | At 7%/yr | At 9%/yr |
|---|---|---|---|---|
| 10 years | €12,000 | €15,500 | €17,400 | €19,500 |
| 20 years | €24,000 | €41,100 | €52,400 | €67,300 |
| 30 years | €36,000 | €83,200 | €121,900 | €184,400 |
| 40 years | €48,000 | €152,600 | €262,000 | €471,600 |
Pre-tax projections. Compound interest calculated monthly. Past market performance doesn't guarantee future results.
You invest €36,000 total over 30 years (€100 × 12 × 30). At 7%, you end up with €121,900. The market added €85,900 on top of your contributions — more than double what you put in.
What Changes If You Start 5 Years Later?
The cost of waiting 5 years before starting, using the 7% scenario:
| Start age | Retire at 65 | Final amount at 7% |
|---|---|---|
| 25 years old | 40 years investing | €262,000 |
| 30 years old | 35 years investing | €180,000 |
| 35 years old | 30 years investing | €122,000 |
| 40 years old | 25 years investing | €81,000 |
Waiting from 25 to 35 costs you €140,000: for the exact same €100/month contribution. That's the price of a 10-year delay.
What €100/Month Represents in Real Life
€100/month is:
- 2-3 restaurant meals
- 1 streaming subscription + coffees
- About €3.30/day
Most people can find €100/month with a budget review. The question is never really the amount — it's the habit. Once the habit exists, most people naturally increase the monthly amount as income grows.
What If You Increase Your Contribution Over Time?
Starting at €100/month and increasing by €50/month each year:
- Year 1: €100/month
- Year 2: €150/month
- Year 3: €200/month…
After 10 years, you'd be at €550/month and your total balance would be roughly €70,000-80,000 at 7% — 4x more than a flat €100/month.
How to Actually Invest €100/Month
- Open a PEA: Trade Republic, BoursoBank, or Bourse Direct (15-30 min online)
- Fund it with €100 on the first month
- Buy 1 ETF share of MSCI World (CW8 or EWLD)
- Set up an automatic monthly investment: most brokers let you do this for €0 extra fee
- Do nothing else: let compound interest work
Track your progress — and earn rewards
TREESTEP shows you your real portfolio value, projected growth, and rewards each monthly contribution with XP and badges. See your wealth tree grow with every investment.
Start for free →Frequently Asked Questions
Is 7% per year realistic?
7% after inflation is the long-run historical average of the MSCI World (50+ years). Individual years vary wildly: -40% in 2008, +30% in 2019. The 7% is a 20-30 year average, not a guarantee for any specific year. A 5% conservative scenario is appropriate for planning purposes.
What if I can only afford €50/month?
Start with €50. At 7% over 30 years, €50/month becomes ~€60,950. That's still significantly better than leaving it in a savings account. The habit and the timeline matter more than the amount.
Should I invest €100/month or save it first?
Both. The classic approach: 1) build your 3-6 month emergency fund first, 2) then start DCA. Once the emergency fund exists, monthly investment starts — don't wait to have more.