Bureau of Labor Statistics > Occupational Requirements Survey > Publications > Factsheets

Strength levels

The Occupational Requirements Survey (ORS) publishes job-related information on physical demands; environmental conditions; education, training, and experience; as well as cognitive and mental requirements. The job requirements reflect those necessary for workers to perform critical tasks in support of the critical job functions, and not the capabilities of individual workers.

The ORS publishes five strength levels (sedentary, light, medium, heavy, and very heavy), which are part of the published physical demands, and are calculated from the weight and duration associated with lifting, carrying, and in some cases, standing.[1]

Chart A data table

Chart A. Percent of civilian workers by strength level, 2021
	Sedentary	Light	Medium	Heavy	Very Heavy
Civilian workers	28.5%	33.3%	28.2%	8.9%	1.1%

Duration levels are used to calculate the amount of time spent lifting or carrying. There are four duration levels in relation to a job's workday schedule: seldom (up to 2 percent), occasional (2 percent to 1/3), frequent (1/3 to 2/3), and constant (2/3 or more).

For example, if workers deliver items weighing between 26-50 pounds occasionally, then the job would be classified as a medium strength level. However, if they delivered slightly heavier items (51-100 pounds) or the duration of carrying or lifting 26-50 pounds increased to being performed frequently, then the job would be classified as a heavy strength level. “Negligible weight” includes anything lifted or carried weighing less than one pound. (See Table 1.)

Table 1. Determining strength level based on lifting or carrying duration or percentage of the workday spent standing
Strength level	Duration of lifting or carrying				Percent of workday standing^[1]
Strength level	Seldom	Occasionally	Frequently	Constantly	Percent of workday standing^[1]
Sedentary work	Up to 10 pounds	Up to 10 pounds	Negligible weight^[2]	No weight	Less than or equal to 1/3^[3]
Light work	11–25 pounds	11–25 pounds	1–10 pounds	Negligible weight^[2]
Medium work	26–50 pounds	26–50 pounds	11–25 pounds	1–10 pounds
Heavy work	51–100 pounds	51–100 pounds	26–50 pounds	11–25 pounds
Very heavy work	>100 pounds	>100 pounds	>50 pounds	>25 pounds
^[1] Standing estimates includes time spent standing, walking, and in low postures. ^[2] Negligible weight includes anything lifted or carried weighing less than 1 pound. ^[3] When the sedentary lifting or carrying requirements are met, and more than 1/3 of the workday is spent standing, light work is required. Source: U.S. Bureau of Labor Statistics, Occupational Requirements Survey.

Sedentary strength level

Strength is considered sedentary when none of the conditions in the strength chart are met and standing is required less than or equal to 1/3 of the work schedule or workday.

Occupations with critical tasks where workers typically spend the day sitting and occasionally lift items of little weight, like a pen or a few pieces of paper, require sedentary strength. (See Table 2.)

Table 2. Percentage of civilian workers with a sedentary strength level by occupation, 2021
Occupation	Estimate	Standard Error
Statistical assistants	100.0	^[1]
Architectural and civil drafters	99.2	0.9
Software developers	98.8	0.6
Financial and investment analysts	98.2	0.7
Computer programmers	97.6	1.3
Management analysts	97.2	1.3
Editors	97.1	1.8
Bill and account collectors	96.9	2.2
Clinical and counseling psychologists	96.6	4.0
Public safety telecommunicators	96.3	1.0
Insurance sales agents	95.9	2.3
Billing and posting clerks	94.8	2.2
Budget analysts	93.0	5.2
Human resources specialists	91.8	1.6
Human resources assistants, except payroll and time keeping	91.5	2.6
^[1] Standard error is less than 0.5. Source: U.S. Bureau of Labor Statistics, Occupational Requirements Survey

Light strength level

If the work level of an occupation does not meet the conditions for the other strength levels, including sedentary, a light strength level is required.[2] Examples of occupations with light strength level requirements include:

Hosts and hostesses (96 percent light strength required) may do activities such as carrying menus and raising and lowering pagers for customers in a queue for 2/3 or more of the workday.
Music directors and composers (80.8 percent light strength required) may carry an instrument over 1 pound for 1/3 to 2/3 of the workday.

Table 3. Percentage of civilian workers with a light strength level by occupation, 2021
Occupation	Estimate	Standard Error
Hairdressers, hairstylists, and cosmetologists	97.7	2.3
Hosts and hostesses, restaurant, lounge, and coffee shop	96.0	1.4
Gambling managers	89.4	8.5
Substitute teachers, short-term	88.9	5.1
Hearing aid specialists	87.5	13.1
Hotel, motel, and resort desk clerks	83.1	7.2
Biological science teachers, post secondary	81.9	4.1
Physics teachers, post secondary	81.9	8.0
Recreation workers	78.2	12.9
First-line supervisors of gambling services workers	78.1	19.1
Waiters and waitresses	77.4	3.9
Opticians, dispensing	75.7	15.8
Dental assistants	74.1	5.2
Teaching assistants, preschool, elementary, middle, and secondary school, except special education	73.3	3.2
Ushers, lobby attendants, and ticket takers	72.9	8.4
Source: U.S. Bureau of Labor Statistics, Occupational Requirements Survey

Medium strength level

For civilian workers, 28.2 percent of workers were required to work at a medium strength level. Examples of occupations with medium strength level requirements include:

Animal caretakers may lift 30 pound bags of grain to feed horses at the racetrack for up to 2 percent of the workday.
Chefs and head cooks may carry a 2 pound tray of cooking supplies to prepare dinner meals for 2/3 or more of the workday.

Table 4. Percentage of civilian workers with a medium strength level by occupation, 2021
Occupation	Estimate	Standard Error
Animal caretakers	88.4	6.5
Tool and die makers	86.5	4.3
Production workers, all other	85.1	9.4
Magnetic resonance imaging technologists	76.8	16.1
Helpers--production workers	76.5	5.5
Museum technicians and conservators	75.7	14.8
Cooks, fast food	74.6	7.6
Chefs and head cooks	73.9	8.7
Multiple machine tool setters, operators, and tenders, metal and plastic	68.9	13.4
Landscaping and groundskeeping workers	66.7	6.6
Grinding, lapping, polishing, and buffing machine tool setters, operators, and tenders, metal and plastic	66.0	11.4
Preschool teachers, except special education	65.3	7.2
Packaging and filling machine operators and tenders	64.4	9.7
Team assemblers	63.3	8.3
Carpenters	62.5	6.3
Source: U.S. Bureau of Labor Statistics, Occupational Requirements Survey

Heavy strength level

For civilian workers, 8.9 percent of workers were required to work at a heavy strength level. Examples of occupations with heavy strength level requirements include:

Construction laborers at a building site may wear a 30 pound tool belt from 1/3 to 2/3 of the workday.
Shipping, receiving, and inventory clerks might lift 15 pound crates for 2/3 or more of the workday.

Table 5. Percentage of civilian workers with a heavy strength level by occupation, 2021
Occupation	Estimate	Standard Error
Light truck drivers	70.1	5.0
Electrical power-line installers and repairers	57.8	13.3
Heating, air conditioning, and refrigeration mechanics and installers	54.9	9.4
Bus and truck mechanics and diesel engine specialists	46.3	7.7
Construction laborers	38.8	5.7
Highway maintenance workers	36.0	6.9
Carpenters	34.7	6.4
Coating, painting, and spraying machine setters, operators, and tenders	34.2	10.1
Recreational vehicle service technicians	34.1	10.0
First-line supervisors of material-moving machine and vehicle operators	30.8	9.0
Heavy and tractor-trailer truck drivers	28.6	3.0
Shipping, receiving, and inventory clerks	28.1	6.5
Multiple machine tool setters, operators, and tenders, metal and plastic	27.4	13.4
Lifeguards, ski patrol, and other recreational protective service workers	25.1	9.0
Furnace, kiln, oven, drier, and kettle operators and tenders	23.8	10.7
Source: U.S. Bureau of Labor Statistics, Occupational Requirements Survey

Very heavy strength level

For civilian workers, 1.1 percent required a very heavy strength level, which indicates requirements beyond the conditions set for heavy work. Examples of occupational groups with heavy strength level requirements include:

Laborers in construction and extraction occupations may lift items that weigh 50 pounds or more, like bags of cement or sheets of plywood, for more than 1/3 of the workday.
Workers in healthcare support occupations may lift patients to and from their beds for 10 minutes during an 8-hour shift.

Table 6. Percentage of civilian workers with a very heavy strength level by occupational group, 2021
Occupation	Estimate	Standard Error
Construction and extraction occupations	1.9	0.6
Transportation and material moving occupations	1.6	0.5
Health care support occupations	1.4	^[1]
Community and social service occupations	0.7	^[1]
Personal care and service occupations	0.7	^[1]
Production occupations	0.3	^[1]
Management occupations	0.1	^[1]
^[1] Standard error is less than 0.5. Source: U.S. Bureau of Labor Statistics, Occupational Requirements Survey

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For additional information on occupational requirements see the ORS homepage or download the ORS complete dataset to explore the latest estimates.

[1] See the sitting and standing factsheet for more information on these requirements.

[2] For more information on work levels, see National Compensation Survey: Guide for Evaluating Your Firm's Jobs and Pay and the Calculation section of the Handbook of Methods.