The way I see it, you have three options when selection an edition of John Calvin’s Institutes of the Christian Religion.

• The final edition of 1559 translated by Henry Beveridge, published in 1867.
• The final edition of 1559 translated by Ford Lewis Battles, published in 1960.
• The French edition of 1541 translated by Robert White, published in 2014.

Beveridge

With Beveridge, you get the full text of the Institutes. The language is somewhat archaic and a bit convoluted sometimes. It’s a lot easier to read than the Puritans. This translation is in the public domain, so you can read it for free online, and printed editions are relatively cheap.

Book 1, Chapter 1, Section 2

On the other hand, it is evident that man never attains to a true self-knowledge until he have previously contemplated the face of God, and come down after such contemplation to look into himself. For (such is our innate pride) we always seem to ourselves just, and upright, and wise, and holy, until we are convinced, by clear evidence, of our injustice, vileness, folly, and impurity. Convinced, however, we are not, if we look to ourselves only, and not to the Lord also—he being the only standard by the application of which this conviction can be produced. For, since we are all naturally prone to hypocrisy, any empty semblance of righteousness is quite enough to satisfy us instead of righteousness itself. And since nothing appears within us or around us that is not tainted with very great impurity, so long as we keep our mind within the confines of human pollution, anything which is in some small degree less defiled delights us as if it were most pure: just as an eye, to which nothing but black had been previously presented, deems an object of a whitish, or even of a brownish hue, to be perfectly white. No, the bodily sense may furnish a still stronger illustration of the extent to which we are deluded in estimating the powers of the mind.

If, at mid-day, we either look down to the ground, or on the surrounding objects which lie open to our view, we think ourselves endued with a very strong and piercing eyesight; but when we look up to the sun, and gaze at it unveiled, the sight which did excellently well for the earth is instantly so dazzled and confounded by the refulgence, as to oblige us to confess that our acuteness in discerning terrestrial objects is mere dimness when applied to the sun. Thus, too, it happens in estimating our spiritual qualities. So long as we do not look beyond the earth, we are quite pleased with our own righteousness, wisdom, and virtue; we address ourselves in the most flattering terms, and seem only less than demigods.

Battles

With Battles, you get the full text in its final form. This is the academic reference edition. If you are going to write a paper or a book, and you want to quote Calvin, use this. The language is much more modern than Beveridge but still a bit technical at times. The biggest downside of this edition is that it comes in two volumes and it’s very expensive.

Book 1, Chapter 1, Section 2

Again, it is certain that man never achieves a clear knowledge of himself unless he has first looked upon God’s face, and then descends from contemplating him to scrutinize himself. For we always seem to ourselves righteous and upright and wise and holy—this pride is innate in all of us—unless by clear proofs we stand convinced of our own unrighteousness, foulness, folly, and impurity. Moreover, we are not thus convinced if we look merely to ourselves and not also to the Lord, who is the sole standard by which this judgment must be measured. For, because all of us are inclined by nature to hypocrisy, a kind of empty image of righteousness in place of righteousness itself abundantly satisfies us. And because nothing appears within or around us that has not been contaminated by great immorality, what is a little less vile pleases us as a thing most pure—so long as we confine our minds within the limits of human corruption. Just so, an eye to which nothing is shown but black objects judges something dirty white or even rather darkly mottle to be whiteness itself. Indeed, we can discern still more clearly from the bodily senses how much we are deluded in estimating the powers of the soul.

For if in broad daylight we either look down upon the ground or survey whatever meets our view round about, we seem to ourselves endowed with the strongest and keenest sight; yet when we look up to the sun and gaze straight at it, that power of sight which was particularly strong on earth is at once blunted and confused by a great brilliance, and thus we are compelled to admin that our keenness in looking upon things earthly is sheer dullness when it comes to the sun. So it happens in estimating our spiritual goods. As long as we do not look beyond the earth, being quite content with our own righteousness, wisdom and virtue, we flatter ourselves most sweetly, and fancy ourselves all bug demigods.

White

With White, you get an earlier version of the Institutes. It’s missing some sections from the final, but not much. This is translated from the French edition which is known for its lively prose. The biggest draw for this edition is its recency, only 2014. The language is very modern and flows nicely. The printed edition costs a bit more than Beverage but still a lot less than Battles. This edition will serve hobbyists well. The newness of the language will provide you with higher likelihood of finishing.

Book 1, Chapter 1, Section 2

Conversely, we observe that no one ever attains clear knowledge of self unless he has first gazed upon the face of the Lord, and then turns back to look upon himself. Deeply rooted in all of us is an arrogance which persuades us that we are righteous, truthful, wise and holy. Only clear evidence that we are unrighteous, deceitful, foolish and vile will convince us of the contrary. We feel no such conviction if all we do is look upon ourselves and not also upon the Lord. He is the one and only standard with which our judgment must accord. But because hypocrisy is something to which we are all naturally prone, we are quite content with an empty show of righteousness rather than with its reality. And because there is nothing around us which is not greatly defiled, whatever is a little less grubby appears to us as purity itself, as long as we confine our attention to the limits of our own—debased—humanity. It is like the eye which, used to seeing only objects that are dark, judges things which are vaguely white or even semi-grey to be the whitest there is. An analogy based on physical sight will help us better understand how badly we misjudge our soul’s powers.

If in broad daylight we look down at the ground or attend to things which are round about us, we have no trouble believing our sight is extremely sharp and keen. When, however, we look straight up at the sun, the power that served us so well on earth is dazed and dazzled by so intense a light, forcing us to admit that our ability clearly to see earthly objects is weak and feeble when it comes to gazing at the sun. This is how it is when we try to estimate our spiritual strengths. As long as we do not look beyond earth’s horizons, we are perfectly content with our own righteousness, wisdom and power. We flatter and congratulate ourselves, and are not far from thinking we are demigods!

Conclusion

In conclusion, let me quote J.I. Packer on the subject of English translations of Calvin’s Institutes:

No English translation fully matches Calvin’s Latin; that of the Elizabethan, Thomas Norton, perhaps gets closest; Beveridge gives us Calvin’s feistiness but not always his precision; Battles gives us the precision but not always the punchiness, and fleetness of foot; Allen is smooth and clear, but low-key.

David W. Hall and Peter A. Lillback, eds. A Theological Guide to Calvin’s Institutes: Essays and Analysis. The Calvin 500 Series. (Phillipsburg, N.J: P&R Pub, 2008), x