Put-Call Parity Calculator

About this calculator

Put-call parity is a no-arbitrage identity linking the prices of a European call and put with the same strike and expiry on the same underlying: C − P = S − K·e^(−rt), where S is the spot price, K the strike, r the risk-free rate, and t the time to expiry. Rearranged, the implied put price is P = C − S + K·e^(−rt).

If the relationship doesn't hold in the market, an arbitrageur can lock in a risk-free profit by simultaneously trading the option, its counterpart, and the underlying — which is why parity holds tightly in liquid options markets. Traders use it to check option prices for mispricing and to construct synthetic positions (e.g., a synthetic long call from a put plus stock).