A 58-year-old patient comes to the physician because of progressive pain and swelling of his left calf for the past 2 days. He has no personal or family history of serious illness. He does not smoke or drink alcohol. His last digital rectal examination and colonoscopy at the age of 50 years were normal. His vital signs are within normal limits. He is 183 cm (6 ft) tall and weighs 80 kg (176 lb); BMI is 24 kg/m2. Physical examination shows redness, warmth, and tenderness of the left calf. The circumference of the left lower leg is 4 cm greater than the right. Dorsiflexion of the left foot elicits pain in the ipsilateral calf. Laboratory studies show:
Hemoglobin 15 g/dL
Leukocyte count 9000/mm3
Platelet count 190,000/mm3
Erythrocyte sedimentation rate 12 mm/h
Serum
Urea nitrogen 18 mg/dL
Creatinine 1.0 mg/dL
Alkaline phosphatase 24 U/L
Aspartate aminotransferase (AST, GOT) 12 U/L
Alanine aminotransferase (ALT, GPT) 10 U/L
Urine
Protein negative
RBC 1/hpf
WBC none
Compression ultrasonography with Doppler shows a non-compressible left popliteal vein with a visible 0.5-cm hyperechoic mass and reduced flow.
The formula for computing Cockcroft-Gault is given by CrCl = ((140 - age) * adjusted weight * (gender_coefficient)) / (serum creatinine * 72), where the gender_coefficient is 1 if male, and 0.85 if female. The serum creatinine concentration is in mg/dL.
The patient's gender is male, which means that the gender coefficient is 1.
The patient is 58 years old. 
The concentration of creatinine is 1.0 mg/dL. 
The formula for computing the patient's BMI is (weight)/(height * height), where weight is the patient's weight in kg and height is the patient's height in m.
The patient's height is 183.0 cm, which is 183.0 cm * 1 m / 100 cm = 1.83 m. The patient's weight is 80.0 kg. The patient's bmi is therefore 80.0 kg / (1.83 m * 1.83 m) = 23.888 kg/m^2.The patient's BMI is 23.9, indicating they are normal weight.
Because the patient is normal, we take take minimum of the ideal body weight and the patient's body as the patient's adjusted weight for the Cockroft-Gault Equation. Hence, the adjusted body weight is the minimum of the two giving us an adjusted body weight of 77.708 kg.

Using the Cockcroft-Gault equation:
CrCl = ((140 - age) * adjusted weight * gender_coefficient) / (serum creatinine * 72).
Plugging the patient's values gives us ((140 - 58) * 77.708 * 1) / (1.0 * 72) = 88.501 mL/min. Hence, the patient's creatinine clearance is 88.501 mL/min.