How to compute a simplified Sharpe ratio

1. Enter mean return %

   "Mean asset return %" is the average return of the asset for the period you're studying, in percent (e.g. 12 for 12%). Use a consistent annualisation if you want an annualised Sharpe.

2. Std dev of returns %

   "Std dev of returns %" is the standard deviation of those returns, also in percent. This proxies the volatility of the return stream. Zero throws "Std dev cannot be 0."

3. Risk-free rate %

   "Risk-free rate %" is the benchmark riskless return (T-bill, OIS, etc.) over the same period; defaults to 0 if you only want excess-over-zero. Negative rates are accepted.

4. Press Run

   Result is sharpe = (meanReturn − riskFreeRate) / stdDevReturn, rounded to 4 decimals. The note flags that the formula uses % inputs as if already scaled — annualise inputs yourself for an annualised Sharpe.