Calculator
Implied volatility calculator
Implied volatility is the volatility that, plugged into Black–Scholes, reproduces the option’s market price. It is how options are compared across strikes and expiries.
Implied volatility
26.99%
- Delta at implied vol
- -0.3598
- Vega at implied vol
- 0.1312
Formula
Find σ such that BlackScholes(S, K, T, r, q, σ) = market price
How to use it
Enter the option’s market price and the same inputs as the Black–Scholes calculator, without volatility.
The solver searches between 0.01% and 500% volatility until the model price matches.
Assumptions and limits
- If the price is below intrinsic value or above the no-arbitrage upper bound, no volatility can match it and the result is shown as unavailable.
- Use mid prices; bid or ask alone will bias the result.
Common questions
Why do different strikes give different implied volatilities?
Because markets price in fatter tails and skew than the model assumes. Plotting IV against strike gives the volatility smile; adding expiries gives the surface.
For education only, not investment advice. Results depend entirely on the inputs and assumptions above; check important numbers independently.