Im trying to clarify this, not sure why I have trouble remembering it so thought if I posted it and got some answers it would help.

Duration of the fixed payer in a swap is Term*.75, so if its a 4 eyar swap, it would be .75*4 = 3

Duration of floating is 1/Settlements per year/2, so i its a 4 year semiannual swap, it would be 1/2/2 =.125

Swap duration = 3-.125 = 2.875 (will be + or - depending on which side you are on).

Is this correct? Also, why do we divide the flaoting by 2? Is that the standard procedure - we just assume that the duration is half the length of the settlement period (kind of like assuming that the fixed is .75 the term of the whole swap)? Thanks!