ALT by age and sex

What’s typical for ALT at every adult age, from a U.S. government health survey of 19,122 people, next to the usual ranges labs print.

NHANES 2015–2016, 2017–March 2020 (pre-pandemic), August 2021–August 202319,122 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

1,530 people in NHANES, 2015–2016, 2017–March 2020 (pre-pandemic), August 2021–August 2023.

Median (half are lower): 15 U/L
Middle half of people: 12 to 21
Middle 90% of people: 8.5 to 39
Usual range a lab prints: 0.0 to 32

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 ALT 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

ALT 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	1,684	7	8	9	11	14	19	29	38	54
30–39	1,512	8	8	10	12	15	20	29	45	57
40–49	1,530	8	8	10	12	15	21	30	39	49
50–59	1,635	9	10	12	14	18	25	33	43	57
60–69	1,920	9	10	11	14	17	23	30	37	51
70–79	1,083	8	9	11	13	16	21	28	35	43
80+	585	8	8	10	12	15	18	23	27	32
All adults	9,949	8	9	10	12	16	22	30	38	52

Men

ALT 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	1,639	9	11	12	15	21	31	49	65	86
30–39	1,306	11	13	15	19	25	35	53	69	88
40–49	1,311	11	13	15	19	25	34	47	57	73
50–59	1,425	11	13	15	19	25	33	45	56	65
60–69	1,802	10	11	13	17	21	28	36	47	56
70–79	1,128	9	10	12	15	19	26	34	42	49
80+	562	8	9	11	12	16	21	27	34	38
All adults	9,173	10	11	13	17	23	31	45	56	73

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 ALT by age, in U/L
Who	Usual range
Women, 1–11	0–28 U/L
Women, 12–17	0–24 U/L
Women, 18+	0–32 U/L
Men, 1–11	0–29 U/L
Men, 12–17	0–30 U/L
Men, 18+	0–44 U/L

Sources: Labcorp, Hepatology, Mayo Clinic Laboratories, American Board of Internal Medicine, MedlinePlus, National Library of Medicine