See what your cash actually earns.
Most people leave their savings in a regular checking or savings account earning almost nothing — losing real money to inflation every year. This tool shows the gap between letting cash sit and letting it work, across the three places people most commonly keep short-term money.
Adjust your starting balance, what you'd add, how often, and over how long. Watch the piggy bank fill up.
How much you have right now
Each weekly
Every week
How long the money stays put
Adjust interest rates+
Defaults reflect typical 2026 rates. Adjust to match your actual account if you want.
That's $7,327 in interest on top of the $27,000 you actually put in.
→ That's $7,257 more than the same money would earn in regular checking.
Where cash actually grows.
Most checking accounts pay almost no interest. Money sits, but it doesn't grow.
Traditional savings at a big bank. Better than checking, but still well below inflation.
Online savings accounts. FDIC-insured. Rate is variable — moves with Fed policy.
Money market accounts work a lot like high-yield savings.
FDIC-insured, similar APYs, sometimes with check-writing or debit access. Often have higher minimum balance requirements. They can be a fine alternative to an HYSA — but watch out for one common mix-up:
For money you won't touch for a while, there are longer-term options.
For cash you can lock up for 6 months to several years, these can sometimes earn a bit more — usually with rules about when you can access it. Each works differently. None of them are "better" or "worse" — they just have different tradeoffs.
Education only. None of these are recommendations — just options worth understanding.
A few things this calculator simplifies.
Interest rates change. Savings APYs aren't fixed. When the Federal Reserve adjusts the federal funds rate, savings rates follow. The 4.5% HYSA rate that looks great today might be 3% in a year — or 6%. The defaults shown reflect typical rates as of early 2026.
Inflation isn't included. Earning 4.5% in an HYSA when inflation is running at 3% means you're really only gaining about 1.5% in purchasing power. That's still better than checking (where you're losing roughly 3% against inflation), but the headline numbers above don't show this.
Taxes matter. Interest earned in any of these accounts is generally taxed as ordinary income at the federal level, plus state tax in most states. So the after-tax interest is lower than the headline. (Tax-advantaged accounts like Roth IRAs are a different story — see those lessons.)
FDIC insurance has limits. FDIC insurance covers up to $250,000 per depositor, per FDIC-insured bank, per ownership category. People with larger balances often spread money across multiple banks for that reason.