Perhaps this will help. Here is what each creed says about the Trinity.
@1689Dave claims that the Athanasian Creed is less developed. For those who do not know, the Athanasian Creed is a 5th Century Creed that is used by the historic church (by the Catholic Church as well as by Presbyterians, Methodists, Lutherans, and most Reformed Baptists) as the criteria for doctrine in regards to the Trinity. It was used to form the Belgic Confession and was instrumental as such at the Synod of Dort (it was held by John Calvin, Beza, and is the "Calvinist" position).
The Chalcedonian Creed (451 AD)
We, then, following the holy fathers, all with one consent teach men to confess one and the same Son, our Lord Jesus Christ, the same perfect in Godhead and also perfect in manhood; truly God and truly man, of a rational soul and body; coessential with the Father according to the Godhead, and consubstantial with us according to the manhood; in all things like unto us, without sin; begotten before all ages of the Father according to the Godhead, and in these latter days, for us and for our salvation, born of the Virgin Mary, the mother of God, according to the manhood; one and the same Christ, Son, Lord, Only-begotten, to be acknowledged in two natures, without confusion, without change, without division, without separation; the distinction of natures being by no means taken away by the union, but rather the property of each nature being preserved, and concurring in one person and one subsistence, not parted or divided into two persons, but one and the same Son, and only begotten, God the Word, the Lord Jesus Christ; as the prophets from the beginning have declared concerning Him, and the Lord Jesus Christ Himself has taught us, and the creed of the holy fathers has handed down to us.
The Athanasian Creed (5th Century AD) as applies to the Trinity
[We] worship one God in trinity and the trinity in unity, neither blending their persons nor dividing their essence. For the person of the Father is a distinct person, the person of the Son is another, and that of the Holy Spirit still another But the divinity of the Father, Son, and Holy Spirit is one, their glory equal, their majesty coeternal. What quality the Father has, the Son has, and the Holy Spirit has.The Father is uncreated, the Son is uncreated, the Holy Spirit is uncreated.
The Father is immeasurable, the Son is immeasurable, the Holy Spirit is immeasurable. The Father is eternal, the Son is eternal, the Holy Spirit is eternal.
And yet there are not three eternal beings; there is but one eternal being. So too there are not three uncreated or immeasurable beings; there is but one uncreated and immeasurable being.
Similarly, the Father is almighty, the Son is almighty, the Holy Spirit is almighty. Yet there are not three almighty beings; there is but one almighty being.
Thus the Father is God, the Son is God, the Holy Spirit is God. Yet there are not three gods; there is but one God.
Thus the Father is Lord, the Son is Lord, the Holy Spirit is Lord. Yet there are not three lords; there is but one Lord.
Just as Christian truth compels us to confess each person individually as both God and Lord, so catholic religion forbids us to say that there are three gods or lords. The Father was neither made nor created nor begotten from anyone. The Son was neither made nor created; he was begotten from the Father alone. The Holy Spirit was neither made nor created nor begotten; he proceeds from the Father and the Son.
Accordingly there is one Father, not three fathers; there is one Son, not three sons; there is one Holy Spirit, not three holy spirits. Nothing in this trinity is before or after, nothing is greater or smaller; in their entirety the three persons are coeternal and coequal with each other.
[We] believe and confess that our Lord Jesus Christ, God's Son, is both God and human, equally. He is God from the essence of the Father, begotten before time [the λόγος]; and he is human from the essence of his mother, born in time; completely God, completely human, with a rational soul and human flesh; equal to the Father as regards divinity, less than the Father as regards humanity.
Although he is God and human, yet Christ is not two, but one. He is one, however,not by his divinity being turned into flesh, but by God's taking humanity to himself. He is one, certainly not by the blending of his essence, but by the unity of his person. For just as one human is both rational soul and flesh, so too the one Christ is both God and human.
Both creeds comprise orthodox doctrine. The latter, however, is more developed.
(Source prca.com, Protestant Reformed Churches)