HI, My Blood Profile Says My Creatinine Serum Is 1.48mg/dl

HI, my blood profile says my Creatinine serum is 1.48mg/dl and my BUN is 17ml/dl shows creatinine is high and BUN is still in normal range but high end of normal. but my BUN and Creatinine ratio is 11 which shows middle of average. i don't get how my Creatinine serum can be high and BUN on high end of normal but my ratio smack dab in the middle of normal?? also how can my urea clearance be calculated? my creatinine clearance is about 95.46. is that normal?