Finance
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Put-Call Parity Calculator.
Calculate the relationship between call, put, stock, strike, and discount values.
Set your values
Results update as you type.
How to Use
This no-arbitrage identity assumes European options, no dividends, and continuously unavailable market data. All quotes and rates are your inputs.
FAQs
How does the put call parity calculator work?
Enter the requested values to receive a deterministic result. No live market, tax, or jurisdiction data is inferred.
Use Cases
Verify Option Pricing Consistency
Traders and analysts use put-call parity to check if quoted option prices are consistent with each other and the underlying asset, helping to spot mispricings.
Example: If a call is priced at $5, spot is $100, strike is $105, r=2%, T=1, the implied put should be $5 + $105*e^(-0.02) - $100 ≈ $7.92.
Find the Missing Option Premium
When only one option premium is available, this calculator derives the fair value of the other option using the parity relationship.
Example: Given a put premium of $3, you can find the call premium that satisfies parity.
Frequently Asked Questions
- What is put-call parity?
- Put-call parity is a financial principle that defines a relationship between the price of a European call option and a European put option with the same strike price and expiration date. It states that the call price plus the present value of the strike price equals the put price plus the current spot price of the underlying asset.
- How is the implied premium calculated?
- The calculator uses the put-call parity formula: Call Premium + Strike Price * e^(-r*T) = Put Premium + Spot Price. If you provide one option's premium, it solves for the other. For example, if you enter the call premium, it calculates the put premium as Call Premium + Strike * e^(-r*T) - Spot Price.
- What inputs do I need to use this calculator?
- You need the underlying spot price, strike price, annual risk-free rate (as a percentage), years to expiry, and at least one of the option premiums (call or put). The calculator will then check parity and compute the missing premium.
Tips & Common Mistakes
Tips
- Ensure the risk-free rate is entered as an annual percentage (e.g., 2 for 2%).
- Use the same time unit for years to expiry (e.g., 0.5 for 6 months).
- This calculator is for European options, which can only be exercised at expiration; put-call parity does not hold for American options.
- Double-check that the spot price and strike price are in the same currency and units.
Common Mistakes to Avoid
- Entering the risk-free rate as a decimal (0.02) instead of a percentage (2).
- Using the wrong time period: ensure years to expiry is in years, not months or days.
- Assuming put-call parity applies to American options, which may have early exercise premiums.
Last updated: August 13, 2026