MAT 14:24: The Greek says that the boat was “many stadia” from land. It is not necessary to express this in any particular unit of measurement. GNT “the boat was far out in the lake” is a good model. (Some Greek manuscripts have “in the middle of the lake” instead of “many stadia from the land.” In either case, neither reading gives a specific measurement; both merely state that the boat was now some distance from the shore, and therefore any phrase that conveys this information will be faithful to the intent of the text.)
LUK 24:13: The distance given here in the best manuscripts is “sixty stadia,” which is about 11 kilometers (7 miles). Some manuscripts have “one hundred sixty stadia,” but this reading cannot be correct. Other ways of expressing “sixty stadia” might be “two hour’s walk” (Leyden, Sranan, Timorese) and “two leagues” (Tzeltal, where “a league” is commonly explained as “one hour’s walk”).
JHN 6:19: English translations generally give “three or four miles” (RSV). Where the metric system is used, you would say “five or six kilometers” (FRCL).
JHN 11:18: In this verse translations generally have “about two miles” (RSV) or “almost two miles.” Where the metric system is used, you would say “about three kilometers.” It would also be possible to say “about a half hour walk.”
REV 14:20; REV 21:16: The numbers in these verses, 1,600 stadia and 12,000 stadia respectively, are probably symbolic and, as such, are more important than the exact distance they might represent. For this reason some translations prefer to retain the numbers and explain the distances in a note or in parentheses in the text. So, for example, ITCL has “twelve thousand stadia (more than two thousand kilometers),” while NIV says “12,000 stadia in length” and adds this footnote: “That is, about 1,400 miles (about 2,200 kilometers).”