Methodology
How Callculator estimates outcomes
The calculator combines option pricing estimates, expiration payoff logic, and user-entered assumptions to show possible strategy outcomes.
Reviewed May 2026
Pricing approach
For non-expiration scenarios, Callculator uses Black-Scholes style estimates for option legs. At expiration, it uses intrinsic value because time value has expired.
- Current implied volatility is used for the estimated entry cost.
- Future implied volatility is used for future scenario values.
- Risk-free rate and dividend yield are user inputs.
Spread calculations
For standard debit spreads, the app prices the long leg and the short leg, subtracts the short leg value from the long leg value, then applies the contract multiplier and position size.
What is excluded
The app does not include commissions, taxes, slippage, margin requirements, assignment risk, exercise decisions, liquidity, or live market quote checks.
Common questions
Why can my broker show a different value?
A broker quote reflects live market prices and bid-ask spreads. Callculator shows a theoretical estimate from your selected assumptions.
Does the app assume European-style exercise?
The theoretical pricing model treats options in a European-style way. American-style exercise and assignment risk should be evaluated separately.
How is capital sizing handled?
The app estimates how many contracts or spreads fit within the capital amount based on the modeled entry cost and the contract multiplier.