Real Return For High Yield (US)
Calculate real returns for US High Yield accounts accounting for taxes and inflation (CPI).
Applied on gross interest earnings (Ordinary Income).
Methodology & Guide
This High-Yield Savings Account (HYSA) calculator projects your capital growth and illustrates the hidden drag that taxes and inflation place on your cash.
1. Calculator Modes
Future Projection: Set your expected future yield and inflation rate to forecast wealth accumulation over a set number of years. Ideal for forward-looking goal setting.
Historical Backtest: Pick a past date range and compute exact returns using actual US CPI inflation data and the historical Fed Funds Rate. This reveals exactly how much purchasing power you would have reliably gained or lost during that specific period in the past.
2. Real Returns & Cash vs. Inflation
High-yield accounts are critical for emergency funds and mitigating portfolio volatility. However, cash historically rarely beats inflation by a large or consistent margin over multiple decades, and you often still lose purchasing power after taxes. Your true wealth accumulation ultimately depends on three distinct variables: the Interest Rate (APY), Inflation (CPI), and your Tax Rate (Federal + State).
3. Taxes on Nominal Yields
In the US, you pay income tax (Federal and generally State) on the nominal interest you earn. Uncle Sam takes his cut of your gross profit before inflation even factors in to erode your purchasing power. For example, states like Texas and Florida have a 0% state income tax, while New York and California can exceed 10%, on top of your federal tax bracket (10% to 37%).
Back-of-napkin Math
A quick heuristic to check if you are losing purchasing power.
r = Gross APY, t = Tax Rate, i = Inflation CPI
Example: Staying Ahead
- HYSA Yield: 4.5%
- Inflation: 3.0%
- Tax Rate: 24%
- Real Result: +0.42%
Example: Losing Power
- HYSA Yield: 4.0%
- Inflation: 3.5%
- Tax Rate: 30%
- Real Result: -0.70%