What Is Normal Specific Gravity?

Specific gravity, a urine concentration test, measures the concentration of all chemical particles in a "clean-catch" (mid-stream) urine sample. Specific gravity measures the ratio of water to chemical particles, which is the urine concentration, or density.

Normal Results

• Normal specific gravity test results fall between the range of 1.020 to 1.028 urine concentration for a patient with normally functioning kidneys. However, MedlinePlus warns that different laboratories may have different normal ranges and recommends talking to your doctor about the meaning of your individual results.

Indication

• A normal result for a specific gravity urinalysis indicates that your kidneys function properly in their ability to balance the amount of water in the urine. Normal urine concentration can also indicate that several diseases or conditions are not present in the patient.

Alternate Test

• Osmolality is another urine concentration test. Osmolality (particles/kg water) is performed the same way (by a clean-catch urine sample) but is a more exact measurement of urine concentration than specific gravity, which is often done as a routine part of urinalysis. Specific gravity tests with normal results often render osmolality tests unnecessary.