Combat Points were first introduced in Pokémon GO as a means for players to be able to look at a Pokémon at a glance and determine if its stats are good or not. In Pokémon Let's Go, Combat Points are used but with more factos involved, it becomes a bit more convoluted.

As Natures exist, and IVs are up to 31, it is calculated a fair bit differently. It takes the stats of the Pokémon at the Level it is before the addition of AVs and then calculates the AVs into it separately. The formula is as follows

CP = floor(((HP+Atk+Def+SAtk+SDef+Spd) * Level * 6 / 100) + (TotalAVs * ((Level / 4) / 100 + 2)))

With this, you'll be able to see the CP of a Pokémon. However, due to variances in natures, getting a perfect CP Pokémon is quite difficult as the higher CP is calculated based on the highest stat being beneficial and the lowest being hindered.

CP is just a visual representation of the strength of a Pokémon and is not a stat in itself.

There is, however, a cap. A Pokémon's CP cannot get above 10,000. While the stats continue to increase where the calculation would end up as more than 10,000, it will just display as 10,000.