Berean Study Bible
Indeed, when Gentiles, who do not have the law, do by nature what the law requires, they are a law to themselves, even though they do not have the law.

King James Bible
For when the Gentiles, which have not the law, do by nature the things contained in the law, these, having not the law, are a law unto themselves:

American Standard Version
(for when Gentiles that have not the law do by nature the things of the law, these, not having the law, are the law unto themselves;

Darby Bible Translation
For when [those of the] nations, which have no law, practise by nature the things of the law, these, having no law, are a law to themselves;

Douay-Rheims Bible
For when the Gentiles, who have not the law, do by nature those things that are of the law; these having not the law are a law to themselves:

English Revised Version
for when Gentiles which have no law do by nature the things of the law, these, having no law, are a law unto themselves;

Young's Literal Translation
For, when nations that have not a law, by nature may do the things of the law, these not having a law -- to themselves are a law;