Nope. Mayans died out before the formula for figuring out what size sphere can fit through a right triangle (in this case, formed by the spandrel, the riser, and the tread) was invented in about 500 BC. And that’s basically the formula you need if you want to try to do the 6" staircase code check with nothing but a tape measure.
It’s impossible for a home inspector to do the 6" staircase code check with with a tape measure alone. A tape measure measures the distance between two points. Describe what two points you would measure? The inside corner of the tread and the riser to the closest point on the spandrel? If that’s what you are doing, you are wrong every time. How about the middle of the tread to the middle of the riser? If that’s what you are doing, you are wrong every time again.
Anyway, you can’t do it without a bit of math.
The way you can tell if s stairwell passes the 6" sphere test is to take 3 particular measurements, add two of them, and subtract the third. If that number is greater than 6", the stairwell fails and is considered a code violation.
I’ll write an article about it with a diagram for you.
However, if you don’t like doing basic math, there is an even easier way…