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Expected Move Calculator

Estimate the expected move into expiry from spot, implied volatility and days remaining — the approximate one standard-deviation range.

Quick answer: The expected move is the approximate one-standard-deviation range the market implies for the underlying by expiry, estimated as spot × IV × √(days ÷ 365). This tool computes it and the 1σ and 2σ ranges.

SpotIV %Days to expiry

How to use it

Enter the spot price, the implied volatility (annualised, %) and days to expiry. The tool estimates the expected (1σ) move as spot × IV × √(days/365) and shows the 1σ (~68% probability) and 2σ (~95%) ranges. It is an approximation that assumes a lognormal distribution.

Frequently asked questions

What is the expected move?

It is the approximate one-standard-deviation range the option market implies the underlying will stay within by expiry, derived from implied volatility and time remaining.

How is the expected move calculated?

Approximately as spot × implied volatility × √(days to expiry ÷ 365). The result is the 1σ move; roughly 68% of the time the underlying is expected to finish within ±1σ.

What does the 2σ range mean?

Two standard deviations, roughly a 95% expected range. It is wider than 1σ and used to gauge less likely but still plausible outcomes by expiry.

Is the expected move a prediction?

No. It is the market's implied range from current option prices, not a forecast of direction. Actual moves can and do exceed it. It is descriptive, not advice.

Runs entirely in your browser — no data leaves your device. Illustrative and educational only; exchange rules and charges apply in practice.