I think you mean a colloquial phrase; "It's ten miles if it's a yard" means that it's definitely ten miles. "He's 80 years old if he's a day" means that he's definitely 80. To be honest, it's kind of old-fashioned, but still good to know.

Use it where you are very certain that some quantity must be at least some value. He/she/it is <some value>, if a <some much smaller value>. More often, I hear it as He is six feet if he is an inch. = He simply MUST be six feet. That boat is 60 feet long if it's an inch. Usually it is said when the speaker is somewhat surprised that someone/something is that big.

1.Generally people will say, " He is 6'1". ->> You also can say, "He is 6 foot, one inch." 2.Generally people would say, " We covered 30 miles." - (3 feet {1 yard} is insignficant, unless it beats a previous goal.) ->>You can also say, "We covered 30 miles and a yard." ** In these statements, you don't use if or a(n) --unless you say, "We would have covered 30 miles, if the weather would have permited it. --or, "He is a six foot tall man.

1 foot 12 inches 1 mile 1760 yards

I don't understand your question or I'd try to help.