Urine Specific Gravity Calculator
Interpret urine specific gravity to assess hydration and kidney function.
Enter your USG reading to see what it means and how to adjust your fluid intake.
Urine specific gravity (USG) measures how concentrated your urine is compared to pure water. Pure water has a specific gravity of exactly 1.000. Urine is always denser than water because it contains dissolved solutes: salts, urea, creatinine, and other waste products.
The measurement:
USG = Urine Density / Water Density
Clinically, this is measured with a urinometer, a refractometer, or a dipstick test. The value reflects how hard your kidneys are working to concentrate or dilute urine in response to your hydration status.
Normal range: 1.010 to 1.025.
Below 1.005: Very dilute. Possible causes include excessive water intake, diabetes insipidus, or certain kidney disorders where concentrating ability is impaired.
1.005 to 1.010: Dilute urine, mild overhydration or early morning void after drinking heavily before bed.
1.010 to 1.025: Normal range. Healthy kidneys adjusting normally to daily fluid intake.
1.025 to 1.030: Concentrated. Mild dehydration is the most common cause. Drink more water.
Above 1.030: Very concentrated. Significant dehydration, high protein intake, or kidney stress. Sustained values above 1.030 warrant medical evaluation.
Athletes sometimes use USG to guide pre-exercise hydration. The American College of Sports Medicine considers USG above 1.020 before exercise a sign of sub-optimal hydration.
One important nuance: first morning urine is naturally more concentrated than samples taken throughout the day, and some medications (diuretics, contrast agents) can artificially alter USG. Interpret readings in context. This calculator is for educational reference — consult a healthcare provider for clinical interpretation.