Volatility converter

Annual ↔ daily, expected move over any horizon.

Interactive: volatility converterMedium

The √time rule in one tool: turn an annualised vol into daily and monthly terms and into the expected move over any horizon.

Annualised volatility % Horizon (days)

Daily vol: —
Monthly vol: —
Expected move (1σ): —
95% range (2σ): —

√252 for trading days; the same rule scales any horizon. It assumes independent daily moves — volatility clustering (below) is exactly where that assumption bends.

The idea behind it

This calculator belongs to Volatility, where the mechanism it computes is explained step by step, with the formula, what each input means and where the simple model stops being right. Everything is computed in your browser; nothing you type is sent anywhere.

More calculators from Volatility

Gamma scalping P&L — convexity against decay, and the breakeven move.
Probability of hitting a barrier — touching is twice as likely as finishing beyond.
What averaging is worth — what “average of the final twelve closes” costs you.
The worst-of term — why a second underlying nearly doubles the breach probability.

All calculators

Not advice. This explains how something works; it is not a recommendation, and nothing here is tailored to you. You can lose everything you put in — with leveraged instruments, considerably more. StrikeAndYield is not a regulated firm and provides no financial services.

The same in full — six points, and why each one matters

No advice, no recommendation. Nothing on this page constitutes investment, financial, legal, tax or accounting advice, a personal recommendation, or an offer or solicitation to buy or sell any financial instrument.
Nothing here is tailored to you. This is written for a general audience. It does not consider your objectives, financial situation, knowledge, time horizon or tolerance for loss.
The examples are simplified. Worked examples use round numbers and leave out costs, spreads, taxes, collateral, settlement and market conventions that materially change real outcomes.
The models are teaching models. Formulas shown are standard textbook formulations. Institutions add calibration, live market data and credit, funding and capital adjustments — nothing here will reproduce a dealer’s quote or produce a valuation you can rely on.
These instruments carry risk. You can lose your entire investment. Leveraged instruments — futures, options, CFDs, perpetual futures and similar — can cost you considerably more than you originally deposited.
We are not a regulated firm. StrikeAndYield is an independent publication by DELISORIA. It is not a bank, broker, fund manager or licensed adviser, it provides no financial services, and reading it creates no client relationship. For decisions about your own money, consult a professional licensed in your jurisdiction. See the full disclaimer.