AST by age and sex

What’s typical for AST at every adult age, from a U.S. government health survey of 19,077 people, next to the usual ranges labs print.

NHANES 2015–2016, 2017–March 2020 (pre-pandemic), August 2021–August 202319,077 adultsAI-verified against cited sources. Awaiting expert review

What’s typical at one age

Pick a sex and an age to see the spread among U.S. adults like that, and type a result to see where it falls.

Age: 45

U.S. women aged 40–49

1,527 people in NHANES, 2015–2016, 2017–March 2020 (pre-pandemic), August 2021–August 2023.

Median (half are lower): 17 U/L
Middle half of people: 14 to 21
Middle 90% of people: 12 to 34
Usual range a lab prints: 8.0 to 43

Shaded: the middle 90% and middle half of people. Dark line: the median. The bracket above: the usual range.

Your result (optional, in U/L)

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Across adult life

NHANES describes the US civilian, non-institutionalized population, not a 'healthy' reference group. People with disease, on medication, fasting or not (except fasting-subsample markers), smokers and so on are all included. A percentile says where a value sits among Americans of that sex and age, not whether it is normal.

How AST varies with age in the U.S.Shaded: middle 90% and middle 50% of people. Line: the median. U/L. Point at any age, or focus the chart and use the arrow keys, to read both sexes in words.

Reference data derived from CDC/NCHS National Health and Nutrition Examination Survey (NHANES), cycles 2015-2016, 2017-March 2020 (pre-pandemic), August 2021-August 2023. Analysis by bloodtesttracker.com; not endorsed by CDC, NCHS or HHS.

Every percentile

Download this table (CSV)

The 25th percentile means a quarter of people in that group had a lower result. In U/L. A dash means too few people were measured for the survey to publish that number.

Women

AST percentiles for U.S. women by age, in U/L, NHANES 2015–2016, 2017–March 2020 (pre-pandemic), August 2021–August 2023
Age	People	2.5th	5th	10th	25th	Median	75th	90th	95th	97.5th
18–29	1,681	11	12	13	14	16	20	25	30	38
30–39	1,511	11	11	12	14	17	20	27	34	45
40–49	1,527	11	12	13	14	17	21	27	34	40
50–59	1,634	12	13	14	16	19	24	29	37	44
60–69	1,914	12	12	14	16	19	23	29	35	44
70–79	1,081	12	13	14	16	20	24	30	35	38
80+	585	12	14	15	17	20	23	28	33	36
All adults	9,933	11	12	13	15	18	22	28	34	42

Men

AST percentiles for U.S. men by age, in U/L, NHANES 2015–2016, 2017–March 2020 (pre-pandemic), August 2021–August 2023
Age	People	2.5th	5th	10th	25th	Median	75th	90th	95th	97.5th
18–29	1,635	13	14	15	17	20	26	34	47	64
30–39	1,300	13	14	15	18	22	26	34	44	56
40–49	1,305	13	14	15	18	21	26	32	42	57
50–59	1,420	13	14	15	18	22	27	35	42	62
60–69	1,795	12	14	15	17	21	25	33	41	49
70–79	1,127	12	13	15	17	20	25	32	37	50
80+	562	11	13	15	17	20	24	29	34	37
All adults	9,144	13	14	15	18	21	26	33	42	56

About these numbers

NHANES describes the US civilian, non-institutionalized population, not a 'healthy' reference group. People with disease, on medication, fasting or not (except fasting-subsample markers), smokers and so on are all included. A percentile says where a value sits among Americans of that sex and age, not whether it is normal.
Assays differ between labs and between NHANES cycles. Values from a commercial lab can sit a few percent higher or lower than NHANES for the same blood. Earlier cycles were bridged to the 2021-2023 method with NCHS equations where NCHS recommends it.
Age 80 and over is top-coded at 80 in public NHANES files, so the 80+ cell mixes everyone 80 and older.
2021-2023 (cycle L) had a 25.7% exam response rate and no race/income oversampling; NCHS advises caution when combining it with earlier cycles.

Centers for Disease Control and Prevention (CDC). National Center for Health Statistics (NCHS). National Health and Nutrition Examination Survey Data. Hyattsville, MD: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, 2015-2016, 2017-March 2020 (pre-pandemic), August 2021-August 2023. https://wwwn.cdc.gov/nchs/nhanes/

How we use survey data

The usual range at every age

The reference range labs print, for each age group. Ranges differ a little between labs, so the range on your own report is the one your result is judged against.

Usual range of AST by age, in U/L
Who	Usual range
Women, 1–13	8–50 U/L
Women, 14+	8–43 U/L
Men, 1–13	8–60 U/L
Men, 14+	8–48 U/L

Sources: Mayo Clinic Laboratories, Labcorp, American Board of Internal Medicine