Here’s a gem I ran across recently while reading the excellent book, Whosoever Will.
And indeed our Lord Jesus was offered to the world. For it is not speaking of three or four when it says: “God so loved the world, that He spared not His only Son.” But yet we must notice what the Evangelist adds in this passage: “That whosoever believes in Him shall not perish but obtain to eternal life.” Our Lord Jesus suffered for all and there is neither great nor small who is not inexcusable today, for we can obtain salvation in Him. Unbelievers who turn away from Him and who deprive themselves of Him by their malice are today doubly culpable, for how will excuse their ingratitude in not receiving the blessing in which they could share by faith.
John Calvin, Sermons on Isaiah’s Prophecy of the Death and Passion of Christ (London: James Clark,  1956), 141
A couple of observations here:
Calvin did not feel the need to restrict “world” to “the world of the elect”. In fact, Calvin appears to take great pains to maximize the scope here since it is apparent that He believes that the scope of the atonement has a direct bearing on the scope of the Gospel message.
Calvin curiously cited unbelievers who reject the Gospel as “doubly culpable”. This is a clear indication that Calvin believed satisfaction for sins to have been made for all persons otherwise one could not be “doubly culpable”.
For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life. -John 3:16, NIV