An option's value is made up of two parts intrinsic value and extrinsic value.
Intrinsic value only exists if your option is in the money. The deeper in the money, the higher the intrinsic value. This means that for a put option with strike 35 and the current underlying price is 30, the intrinsic value is (35-30) which is 5. If the current underlying price is 40 with the strike at 35, the intrinsic value is 0 because there is no such thing as negative intrinsic value. Similarly for calls, if the strike is 35 and the current price is 40, the intrinsic value for the call is (40-35) which is 5.
Extrinsic value is made up of implied volatility and time value. Implied volatility as the name implies, refers to how much the underlying is expected to move. This is why companies like TSLA (which can swing up to 10% in a single trading day) has a higher implied volatility than say Coca-Cola which usually trades within 0-1% in a single trading day.
Time value refers to how much time is left in the option. More time allows the underlying to move more which gives it more chance to move in the money. As such, longer dated options will be more expensive, all else constant.
Of course, if you're trying to calculate the exact fair value, there is a formula known as the Black Scholes Pricing Model which is used to compute it. But do note that the price of an option is ever changing so I'm not sure that there is much utility in doing so.
An option's value is made up of two parts intrinsic value and extrinsic value.
Intrinsic value only exists if your option is in the money. The deeper in the money, the higher the intrinsic value. This means that for a put option with strike 35 and the current underlying price is 30, the intrinsic value is (35-30) which is 5. If the current underlying price is 40 with the strike at 35, the intrinsic value is 0 because there is no such thing as negative intrinsic value. Similarly for calls, if the strike is 35 and the current price is 40, the intrinsic value for the call is (40-35) which is 5.
Extrinsic value is made up of implied volatility and time value. Implied volatility as the name implies, refers to how much the underlying is expected to move. This is why companies like TSLA (which can swing up to 10% in a single trading day) has a higher implied volatility than say Coca-Cola which usually trades within 0-1% in a single trading day.
Time value refers to how much time is left in the option. More time allows the underlying to move more which gives it more chance to move in the money. As such, longer dated options will be more expensive, all else constant.
Of course, if you're trying to calculate the exact fair value, there is a formula known as the Black Scholes Pricing Model which is used to compute it. But do note that the price of an option is ever changing so I'm not sure that there is much utility in doing so.