Volatility Calculator
Volatility quoted over one period means little until it's on a common footing. This scales a per-period volatility to an annualized figure — the standard way to compare risk — using the square-root-of-time rule, and shows the daily and monthly equivalents.
- • Annualized = per-period volatility × √(periods per year).
- • Common periods per year: 252 trading days · 52 weeks · 12 months.
Worked example: 1% daily volatility → 1% × √252 ≈ 15.9% annualized.
Square-root-of-time assumes returns are independent day to day and volatility is stable — real markets cluster (calm stretches, then bursts), so a single annualized number hides how lumpy the ride actually was. Educational tool, not advice.
A free, interactive calculator for any blog, newsletter or forum — same numbers as here, and it links back.
<iframe src="https://stratsemble.com/embed/tools/volatility-calculator" width="460" height="380" style="border:0;border-radius:12px;max-width:100%" loading="lazy" title="Volatility calculator — Stratsemble"></iframe>A calculator shows what a rule should do on paper. A backtest is how you find the rare few that actually beat simply buying and holding — costs on, losses shown, no look-ahead — so when you build one that survives, you'll know it isn't a fake edge, and can prove it forward before you risk real money. It won't tell you you'll win — nothing honest can.