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Urine Specific Gravity: Normal Range and What High or Low Means

What the specific gravity of urine measures, the usual 1.005 to 1.030 range, what high and low results can mean, and how hydration and the time of day change the number.

Published

August 10, 2024

Last updated

November 2, 2026

Read time

5 min read

Medically reviewed by

Rhonda Collins, FNP-C

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Urine specific gravity measures how concentrated your urine is: it shows the total concentration of all the chemical particles in it ^[1]. The usual normal range is 1.005 to 1.030, although ranges vary slightly between laboratories, so read your result against the range on your own report ^[1][2]. A higher number means more concentrated urine and a lower number means more dilute urine. Most of the time, the result reflects how much you have had to drink ^[3][4].

What does urine specific gravity measure?

Urine specific gravity (often shortened to SG or USG) is a measure of urine concentration. It reflects both your current hydration and the kidneys’ ability to concentrate urine when the body needs to hold on to water ^[3].

Specific gravity is usually measured with a color-sensitive dipstick pad as part of a routine urinalysis. A dipstick gives only a rough result, and a laboratory measurement is more accurate ^[1]. Urine osmolality is a more specific and precise test of urine concentration, but specific gravity is easier and more convenient ^[1]. The two results correlate with each other ^[3].

On a Mito report, specific gravity is listed with the other urine results. It is reported separately from urine pH, which measures how acidic or alkaline the urine is rather than how concentrated it is.

What is the normal range for urine specific gravity?

MedlinePlus and Cleveland Clinic list a normal range of 1.005 to 1.030 ^[1][2]. A review in American Family Physician gives a slightly wider normal range of 1.003 to 1.030 ^[3]. Within that range, the number mostly reflects hydration:

• Near 1.010: suggests normal hydration ^[4].
• Below 1.010: suggests relative hydration, meaning dilute urine ^[3].
• Above 1.020: suggests relative dehydration, meaning concentrated urine ^[3][4].
• Below about 1.003: suggests marked dilution of the urine ^[4].

These cutoffs describe hydration at the moment the sample was taken. They are not a diagnosis on their own.

What does high urine specific gravity mean?

High urine specific gravity means your urine is more concentrated than usual. Often this reflects low fluid intake or loss of body fluids (dehydration) ^[1][3][4].

Other causes of increased specific gravity include ^[1][3][4]:

• Dehydration, meaning loss of body fluids.
• Glucose in the urine, which adds dissolved particles. High blood sugar, as in uncontrolled diabetes, is the usual reason. See urine glucose.
• Syndrome of inappropriate antidiuretic hormone (SIADH), a hormone condition.
• Heart failure, shock, or narrowing of the kidney artery (renal artery stenosis).
• A high blood sodium level (hypernatremia).

Some substances make specific gravity read higher than the urine’s true concentration. These include protein in the urine, dextran solutions, and the contrast dye given into a vein for imaging scans ^[1][3]. If your report also shows protein in the urine, that can push the specific gravity reading up.

What does low urine specific gravity mean?

Low urine specific gravity means your urine is more dilute than usual. Drinking a lot of fluid is one cause ^[1].

Causes of decreased specific gravity include ^[1][3][4]:

• Drinking a lot of fluid, including water intoxication at the extreme.
• Diuretic medicines, which make the kidneys pass more water.
• Diabetes insipidus, which causes very dilute urine.
• Kidney problems, such as kidney failure, damage to the kidney tubules, or a severe kidney infection (pyelonephritis).
• A low blood sodium level (hyponatremia).
• Aldosteronism, a condition of too much of the hormone aldosterone.

In people with kidney disease that affects the kidney tissue itself (intrinsic renal insufficiency), specific gravity can become fixed at 1.010. That is the specific gravity of the fluid the kidneys first filter from the blood ^[3]. Alkaline urine can make the dipstick read falsely low ^[3].

How do hydration and timing affect urine specific gravity?

The time of day you give the sample changes the number. Urine collected first thing in the morning, after a night without drinking, is usually more concentrated than a sample taken later in the day. In one study of adults, the median specific gravity was 1.018 for fasted first-morning samples and 1.011 for non-fasted spot samples taken later. About 42% of the first-morning samples read 1.020 or higher, compared with about 22% of the later samples ^[5].

Recent drinking matters too. Drinking a lot of fluid lowers specific gravity, and limiting fluids raises it. That is why a test of how well the kidneys concentrate urine may ask you to limit fluids for 12 to 14 hours beforehand ^[1]. Specific gravity also lags behind fast changes in hydration. In a study of 51 people tested as they dehydrated and then rehydrated, urine specific gravity changed later than a blood measure of hydration, and at the best cutoff only about 65% of athletes were classified correctly ^[6]. A single result is a snapshot, not a precise hydration score.

Some medicines (including dextran and sucrose), recent anesthesia, contrast dye for imaging, and herbal remedies can also affect the result, so mention them when you test ^[1].

For related lifestyle information, see our guide to improving urine specific gravity.

When should I talk with a clinician about urine specific gravity?

Talk with your clinician if your specific gravity stays high or low on repeat tests even though your fluid intake is normal, or if it comes with other abnormal urine results such as glucose or protein. Urine osmolality is the more precise follow-up measure of urine concentration ^[1].

Urine specific gravity testing with Mito

The Specific Gravity, Urine Test is the individual test for urine specific gravity. If you also want the other dipstick and microscopy results, such as glucose, protein, pH, and ketones, the Urinalysis, Routine Test reports specific gravity as part of the full urinalysis. Check the product page for current pricing and availability.

Related Urine Specific Gravity Resources

• How to Improve Your Urine Specific Gravity Level Naturally

• Urine pH

References

1. MedlinePlus Medical Encyclopedia: Urine specific gravity test
2. Cleveland Clinic: Urinalysis
3. Simerville JA, Maxted WC, Pahira JJ. Urinalysis: A Comprehensive Review. Am Fam Physician. 2005
4. Hitzeman N, Greer D, Carpio E. Office-Based Urinalysis: A Comprehensive Review. Am Fam Physician. 2022
5. Wilson PB, Ferguson BK, Winter IP. Time of urine sampling may influence the association between urine specific gravity and body composition. PLoS One. 2025
6. Oppliger RA, Magnes SA, Popowski LA, Gisolfi CV. Accuracy of urine specific gravity and osmolality as indicators of hydration status. Int J Sport Nutr Exerc Metab. 2005

Frequently asked questions

What is a normal urine specific gravity?

MedlinePlus and Cleveland Clinic list 1.005 to 1.030 as the normal range, and some clinical references give 1.003 to 1.030. Ranges vary slightly between laboratories, so compare your result with the range printed on your own report.

Is a urine specific gravity of 1.030 high?

A value of 1.030 sits at the top of the usual normal range. It means the urine is very concentrated, which often reflects low fluid intake or fluid loss, and first-morning samples tend to read higher. Values above 1.020 are commonly read as relative dehydration.

Is a urine specific gravity of 1.005 too low?

A value of 1.005 is at the bottom of the usual normal range and means dilute urine, which can follow drinking a lot of fluid. Values below about 1.003 suggest marked dilution, which can come from drinking a great deal of water or from conditions such as diabetes insipidus.

Does drinking water lower urine specific gravity?

Yes. Drinking more fluid makes urine more dilute, so specific gravity falls. Drinking too much fluid is one of the listed causes of low specific gravity, and a sample taken soon after a large drink will usually read lower than a first-morning sample.

What does a specific gravity of 1.010 mean?

A value near 1.010 suggests normal hydration. In people with kidney disease that affects the kidney tissue itself, specific gravity can become fixed at 1.010, the specific gravity of the fluid the kidneys first filter from the blood.