Tools in This Collection
I Bond Calculator
Project I-bond value with composite rate, early withdrawal penalty, and redemption timeline
Treasury Bill Calculator
Calculate T-bill discount yield, investment yield, and annualized return from purchase price
Bond Yield Calculator
Calculate current yield and yield-to-maturity for bonds from price and coupon rate
Net Worth Calculator
Total your assets minus liabilities to calculate current net worth and track it over time
Net Worth Percentile Calculator
Find your net worth percentile by age group using Federal Reserve survey data
Spending Percentile Calculator
See if you overspend or underspend compared to national averages across spending categories
Guides & Articles
Savings and Interest Workflow
Conservative savers and those with near-term cash needs have more options than a standard savings account. From I-bonds to Treasury bills to high-yield savings, the after-tax yield difference between the best and worst options can be 2-4% annually — meaningful on any significant cash balance.
I-Bonds: Inflation Protection with a Lock-Up
I-bonds earn interest tied to the CPI inflation rate, updated semi-annually each May and November. They're guaranteed to never lose nominal value and are backed by the US government. The trade-offs: a 12-month minimum holding period, a 3-month interest penalty for early redemption in the first 5 years, and a $10,000 annual purchase limit per person. The I Bond Calculator shows the current composite rate, projected value, and effective yield after accounting for any penalties.
Treasury Bills: Short-Term Safety with Good Yields
T-bills are short-term government debt (4, 8, 13, 17, 26, and 52-week maturities) sold at a discount to face value. They're exempt from state income taxes, which improves their after-tax yield in high-tax states like California and New York. The Treasury Bill Calculator converts between discount yield and investment yield, and shows the effective annualized return for any holding period.
Tracking Net Worth Over Time
Net worth — total assets minus total liabilities — is the single most comprehensive measure of financial health. The Net Worth Calculator provides a clean structure for listing all assets (savings, investments, real estate, vehicles) and liabilities (mortgages, loans, credit card balances). Tracking this quarterly or annually shows whether you're actually building wealth, independent of income fluctuations.
Frequently Asked Questions
Are I-bonds a good investment right now?
I-bonds make the most sense during high inflation periods when the composite rate significantly exceeds HYSA rates. When inflation is moderate (2-3%), HYSA rates may be competitive or better without the 12-month lock-up and $10,000 annual limit. The I Bonds vs HYSA Comparison article analyzes the current trade-offs in detail.
What is the difference between T-bill discount yield and investment yield?
Discount yield is calculated on the face value of the T-bill. Investment yield (also called bond equivalent yield) is calculated on the purchase price, which is lower than face value. Investment yield more accurately represents the return on money actually invested. The Treasury Bill Calculator shows both and converts between them.
Is there a state income tax advantage to Treasury bills?
Yes. Interest on US government obligations (including T-bills, T-notes, T-bonds, and I-bonds) is exempt from state income tax. In high-tax states like California (13.3% top rate), New York (10.9%), or New Jersey (10.75%), this exemption can add 0.5-1.5% to the effective after-tax yield compared to a bank HYSA that pays the same nominal rate.
What is a good net worth by age?
Net worth benchmarks vary widely. The Federal Reserve's Survey of Consumer Finances shows the median net worth for Americans age 35-44 is around $91,000; for 45-54, approximately $169,000; for 55-64, approximately $213,000. The Net Worth Percentile Calculator shows exactly where you fall relative to your age group using this survey data.
How do I calculate bond yield to maturity?
Yield to maturity (YTM) is the total return anticipated if a bond is held to maturity, accounting for coupon payments, price, face value, and time remaining. It's the internal rate of return of holding the bond. The Bond Yield Calculator computes YTM along with current yield and modified duration.