How do you intend to account for the progressive clean up from the landing configuration to the missed approach configuration to the enroute configuration .. with varying gradient capabilities throughout ? Not to mention the hills here and there and the possible need for turns ?
On the airbus these figures are presented on three charts. For a missed approach we select TOGA, gear up, and move flaps up one step to conf 3, conf 2, or conf 1+F. From their respective charts we can see the expected climb gradient and as long as it is equal to or greater than the required gradient all is good. This required gradient is listed on lido charts. It is 2.5% or a non standard requirement. Also if a turn is required we must allow for 0.9%. We maintain that configuration until the missed approach altitude is reached where we level off and clean up to hold or enroute speeds.
As with most things there is more than 1 way to skin a cat. Other options are available if required gradients are not attainable.