Financial Calculators
Fill in your numbers, then click Calculate to open the full page and get a shareable link.
Compound Interest Calculator
Step 1 · Initial Investment
Amount of money available to invest initially.
Step 2 · Contribute
Use a negative number for monthly withdrawals.
How long you plan to save.
Step 3 · Interest Rate
Your estimated annual rate.
Range above and below the rate to model.
Step 4 · Compound It
Times per year that interest will be compounded.
Retirement Savings Longevity Calculator
Grows with inflation each year. Defaults to ~4% of the starting balance — the classic 4% rule. Adjust up or down for your situation.
Want a more realistic view?
This basic version assumes a single, steady rate of return every year. Markets don't actually work that way — returns vary, and bad years early in retirement hurt much more than bad years late ("sequence-of-returns risk").
The Advanced Portfolio Longevity Simulator (Premium) runs your actual ticker mix through historical returns and 1,000 Monte Carlo scenarios to estimate the probability your portfolio survives.
Time Value of Money Calculator
What the money is worth today.
Expected yearly return or discount rate.
How far into the future.
How often the return compounds.
What is the time value of money?
A dollar today is worth more than a dollar tomorrow — because money can earn a return. The time value of money (TVM) measures exactly how much more.
For example, $30,000 invested at 7% annually for 15 years grows to about $82,771. That's the power of compounding: your return earns its own return, year after year.
You can also flip the math: if you need $60,000 in 15 years and expect 7% returns, you only need to set aside about $21,703 today.
Rule of 72 Calculator
Enter the expected annual interest rate or return.
What is the Rule of 72?
The Rule of 72 is a quick mental math shortcut to estimate how long it takes for an investment to double at a fixed annual rate of return. Simply divide 72 by the interest rate to get the approximate number of years.
For example, at 8% annual return: 72 ÷ 8 = 9 years to double your money. The actual time (using the exact logarithmic formula) is about 9.01 years — remarkably close.
This rule works well for rates between 6% and 10%. It becomes less accurate at very low or very high rates.
Estate & Gift Tax Calculator
Estimate federal estate tax and state death tax on your gross estate.
Estate Details
Tax Settings
This calculator is designed to be informational and educational only, and does not constitute tax or legal advice. Consult a qualified estate planning attorney or tax professional for your specific situation.
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