Free calculator · Investing in Public
The first $100,000 is the hardest. Here's your date.
Charlie Munger said the first hundred grand is a bitch, and you have to do it. He was right — and this shows you exactly why. Put in your numbers and watch how much faster the second one arrives.
- Free, no signup
- About 30 seconds
- Saved in your browser
Your numbers
An assumption, not a promise. Markets don't return the same number twice.
The curve
Who's doing the work
Email me my numbers
I'll send your timeline plus the three things that actually move it. No spam.
Check your email
Confirm your address and your numbers are on the way.
The math
Why every $100,000 comes faster
No black box. Here's every step, using the default numbers: $10,000 invested, $1,000 a month, 7% a year.
Every month
balance × (rate ÷ 12) + your deposit
At $100,000, $100,000 × 7% ÷ 12 ≈ $583 of growth lands before you add a dollar.
Who built it
growth = balance − what you put in
Your first $100K is 79% your money. Your third is only 41% your money. Growth built the rest.
The payoff
same deposit + a bigger balance working
First $100K: 5y 10m. Second: 4y 6m. Third: 3y 5m. You didn't change a thing.
Questions
The honest answers
How long does it take to invest $100,000?
It depends on what you start with and what you add each month. With $10,000 already invested, $1,000 a month and a 7% assumed return, this calculator lands at 5 years and 10 months. Starting from zero, the same $1,000 a month takes 6 years and 8 months.
Why does the second $100,000 come faster?
Because the first one starts working. At a 7% assumed return, a $100,000 balance adds about $583 a month on its own (100,000 × 7% ÷ 12), so the same monthly deposit gets help it didn't have at the start. With the default numbers, growth builds 21% of your first $100,000, 46% of the second and 59% of the third.
What return should I assume?
The default is 7% a year. Treat it as a planning assumption, not a forecast. Real markets never deliver a smooth 7%; some years are up a lot and some are down. Slide it to 4% or 5% to see a more conservative date and read the result as a range, not a promise.
Does this include taxes, fees or inflation?
No. It's a straight compound growth projection: growth is added monthly at the rate you pick and your deposit lands at the end of each month. Taxes, fund fees and inflation would all push your date out, so slide the return down if you want a cushion.
Is my data saved or sent anywhere?
Your numbers are saved in this browser only. Nothing is uploaded unless you choose to email yourself the results, in which case your starting amount, monthly amount and timeline are attached to that signup.
Is this financial advice?
No. It's arithmetic on numbers you enter. It doesn't know your taxes, your timeline or your risk. Use it to see the shape of the road, then do your own research.
Keep going
The other two tools I actually use
Build the pile, decide how to split it, then turn it into income. This calculator is step one.
The Investing DNA Worksheet
Five questions decide how your money should split across Growth, Dividend Growth and High Income.
Find your split → Step three · Turn it into incomeThe Dividend Coverage Tracker
See what percentage of your monthly bills your dividends already pay, and how much more you'd need invested.
Get your Coverage Number → ReadMy 3-bucket portfolio
The Growth, Dividend Growth and High Income buckets I run, and why I run it this way.
Read the post →Not financial advice. This calculator is for educational and entertainment purposes only. It is a compound interest projection based on assumptions you enter, not a prediction, guarantee, or recommendation. Actual returns vary and can be negative; markets do not deliver a steady annual rate. I am not a financial advisor, broker, or tax professional, and nothing here is financial, investment, or tax advice. Investing involves risk, including the possible loss of principal. Taxes, fees, and inflation are not accounted for. Always do your own research and consult a licensed professional before making any investment decision.