Why is the standard hemoglobin level is different for women and man?

Question

Why is the standard hemoglobin level is different for women and man?

Answer 1

http://en.wikipedia.org/wiki/Hemoglobin

The percentage or level of haemoglobin depends on the total number of red blood cell in the blood.

On average,the Total volume of blood in men is always higher than in women and also men have approx. 5 millions of red blood cells, where as  in women around 4.5 millions. (just roughly estimated)

As you know that haemoglobin is the main constituent of red blood cell.

So, if the  amount of red blood cells would be less in women by about 1/2 million in respect to men, automatically the haemoglobin level (%) would be less too in comparison with men.