The tefach /tofach is the width of the hand at the base of the fingers, not including the thumb.
EXO 25:25; EXO 37:12; 1KI 7:26; 2CH 4:5: In many languages it will be possible to express these words as the Hebrew does, as the width of a hand. Otherwise a measurement such as “8 centimeters” (FRCL) or “3 inches” (GNT) will do. For some reason CEV and NCV have “three inches” in the Exodus references but “four inches” in 1 Kings and 2 Chronicles.
EZK 40:5; EZK 43:13: Here the cubit is said to be longer by one tofach. This is the measure used throughout chapters 40–48 of Ezekiel. The shorter cubit actually measured about 45 centimeters (18 inches), and this longer one would have been 53 centimeters (21 inches). Some translations try to reflect the difference. Many, however, will prefer to use a rounded-off value of 50 centimeters (18 inches) for both.
PSA 39:6: Here the word tefach (tapchah) is a symbolic figure indicating the shortness of life. This may be the basis for the statement of Jesus in MAT 6:27. See the discussion under pēchus below.