Investing education and calculators
Learn how money compounds, shrinks and recovers.
Articles, research notes and calculators that work through returns, losses, fees and inflation, with the assumptions printed next to every figure. You change the inputs; the arithmetic follows.
Education and tools only. Nothing here is personalized advice or a recommendation.
4% a year
- Year 10
- $14,802
- Year 20
- $21,911
- Year 30
- $32,434
6% a year
- Year 10
- $17,908
- Year 20
- $32,071
- Year 30
- $57,435
8% a year
- Year 10
- $21,589
- Year 20
- $46,610
- Year 30
- $100,627
$10,000 with no additions, before fees, taxes and inflation. The three returns are assumptions chosen to show the spread, not predictions. Bar length is the same scale in all three groups.
Worked arithmetic, not market data
Five numbers worth working out once
Each figure is calculated from the assumption beside it, and each has a calculator behind it so you can change the assumption. This site shows no live prices and makes no forecasts.
Rule of 72
12 years
to double money at 6% a year (72 ÷ 6)
Getting back to even
+100%
gain needed after a 50% loss
Fee drag
24.8%
of a 30-year balance lost to a 1% yearly fee, at 6% before fees
Inflation
23 years
for 3% inflation to halve what money buys
Compounding
$76,123
from $10,000 at 7% a year for 30 years
Try the numbers yourself
Calculators that run in your browser
- T-01Compound growth calculatorSee how balance grows from a starting amount, a monthly addition, and a rate you choose.
- T-02Portfolio allocation analyzerSet weights across asset buckets and see concentration or drift.
- T-03Options profit / loss calculatorSketch an option position and see where you gain, lose, and break even.
- T-04Drawdown recovery calculatorTurn a percent loss into the gain needed to get back to even.
Two more worked examples
How rate and loss change the outcome
What $10,000 becomes in 10 years
Arithmetic, not a forecast. Each bar assumes the same return every year, reinvested, with no fees, tax or withdrawals. Real returns vary from year to year.
What it takes to recover a loss
| If you lose | You need to gain |
|---|---|
| -10% | +11.1% |
| -25% | +33.3% |
| -50% | +100% |
| -75% | +300% |
A gain of loss ÷ (100 − loss). It is why limiting large drawdowns matters more than it first looks. The drawdown calculator lets you test your own numbers.
From the research library
Research notes
- Quantitative investingHow rules-based approaches differ from story-driven trading.
- Risk managementDrawdowns, concentration, liquidity, and sequence risk in plain terms.
- Options and derivativesPayoffs, limits, and vocabulary explained before any strategy talk.
- Macroeconomic contextRates, inflation, and credit conditions as background, not headlines.
Strategy library
Longer reads, by situation
- Quantitative strategyFor readers who like rules and data more than headlines.
- Tactical asset allocationFor readers adjusting risk as conditions change.
- High-net-worth portfolio structuringFor households with several accounts or concentrated positions.
- Risk-managed investingFor people who want returns but worry about large losses.
Contact us
A message to our own team — no matching, no third party.
- Read the research or run a tool to frame your question.
- Tell us what you need: a trading algorithm to build and deploy, investment or portfolio advice, or access to a private fund.
- A person on our own team reads your message and replies directly, by phone or email.