Where Plumbers Are Concentrated: Plumbers per 1,000 Jobs and Helper Ratios by State
The short answer
Louisiana has the highest concentration of plumbers in the US, 4.32 per 1,000 jobs, a location quotient of 1.44, and the District of Columbia the lowest at 1.43, according to BLS Occupational Employment and Wage Statistics for May 2025. Nationally there are 9.5 plumber helpers for every 100 plumbers, but the ratio runs from 24.0 in Louisiana to 4.4 in Wisconsin.
What the table shows
Raw plumber counts follow population: California, Texas, Florida and New York lead simply because they are large. The location quotient strips that out. It compares the share of a state’s jobs held by plumbers with the share nationally, so a quotient of 1.30 means plumbers are 30 percent more concentrated in that state’s workforce than in the country as a whole. The helper ratio adds a second dimension: how many helpers, the occupation BLS uses for plumbing assistants, work alongside each hundred plumbers. Plumbers who work for themselves are counted separately in self-employed plumbers by state.
| State | Plumbers | Per 1,000 jobs | Location quotient | Helpers | Helpers per 100 plumbers |
|---|---|---|---|---|---|
| Louisiana | 8,360 | 4.32 | 1.44 | 2,010 | 24.0 |
| Maine | 2,710 | 4.23 | 1.41 | suppressed | n/a |
| Maryland | 11,420 | 4.13 | 1.38 | 970 | 8.5 |
| Wyoming | 1,140 | 4.05 | 1.35 | 40 | 3.5 † |
| Utah | 7,030 | 4.05 | 1.35 | 390 | 5.5 |
| Nebraska | 4,110 | 4.01 | 1.34 | 70 | 1.7 † |
| Hawaii | 2,500 | 3.99 | 1.33 | 180 | 7.2 † |
| South Dakota | 1,760 | 3.84 | 1.28 | 210 | 11.9 † |
| North Dakota | 1,620 | 3.77 | 1.26 | suppressed | n/a |
| Massachusetts | 13,460 | 3.70 | 1.24 | suppressed | n/a |
| Alaska | 1,200 | 3.70 | 1.23 | 100 | 8.3 † |
| Iowa | 5,730 | 3.68 | 1.23 | 350 | 6.1 † |
| Arizona | 11,810 | 3.65 | 1.22 | 460 | 3.9 † |
| Montana | 1,860 | 3.64 | 1.22 | 110 | 5.9 † |
| Rhode Island | 1,820 | 3.64 | 1.21 | suppressed | n/a |
| Minnesota | 10,720 | 3.63 | 1.21 | suppressed | n/a |
| Idaho | 3,090 | 3.60 | 1.20 | suppressed | n/a |
| Oklahoma | 6,050 | 3.54 | 1.18 | 740 | 12.2 |
| Indiana | 11,280 | 3.52 | 1.18 | 390 | 3.5 † |
| Washington | 12,470 | 3.51 | 1.17 | 600 | 4.8 |
| Colorado | 10,080 | 3.51 | 1.17 | 240 | 2.4 † |
| Wisconsin | 10,210 | 3.47 | 1.16 | 450 | 4.4 |
| Nevada | 5,370 | 3.46 | 1.15 | 350 | 6.5 † |
| Virginia | 13,780 | 3.35 | 1.12 | 1,640 | 11.9 |
| Alabama | 6,950 | 3.29 | 1.10 | 770 | 11.1 |
| Delaware | 1,590 | 3.28 | 1.10 | 140 | 8.8 † |
| New Mexico | 2,830 | 3.25 | 1.09 | 400 | 14.1 |
| Vermont | 980 | 3.23 | 1.08 | 140 | 14.3 † |
| Michigan | 14,120 | 3.21 | 1.07 | 270 | 1.9 † |
| Connecticut | 5,410 | 3.19 | 1.07 | 160 | 3.0 † |
| Kansas | 4,590 | 3.19 | 1.06 | 320 | 7.0 † |
| Kentucky | 6,360 | 3.18 | 1.06 | 960 | 15.1 |
| Texas | 44,090 | 3.13 | 1.05 | 7,210 | 16.4 |
| Ohio | 16,390 | 2.95 | 0.99 | 1,090 | 6.7 |
| Florida | 29,260 | 2.95 | 0.98 | 4,500 | 15.4 |
| North Carolina | 14,510 | 2.94 | 0.98 | 3,070 | 21.2 |
| Mississippi | 3,360 | 2.89 | 0.96 | 400 | 11.9 |
| New Hampshire | 1,950 | 2.86 | 0.95 | 70 | 3.6 † |
| Missouri | 8,310 | 2.83 | 0.95 | 280 | 3.4 † |
| Tennessee | 9,270 | 2.83 | 0.94 | 1,100 | 11.9 |
| Illinois | 16,750 | 2.75 | 0.92 | suppressed | n/a |
| Oregon | 5,370 | 2.73 | 0.91 | 210 | 3.9 † |
| California | 47,660 | 2.62 | 0.87 | 2,500 | 5.2 |
| West Virginia | 1,830 | 2.61 | 0.87 | 130 | 7.1 † |
| Arkansas | 3,370 | 2.59 | 0.86 | 330 | 9.8 † |
| South Carolina | 5,770 | 2.50 | 0.84 | 1,090 | 18.9 |
| New York | 23,210 | 2.40 | 0.80 | 4,840 | 20.9 |
| Pennsylvania | 13,620 | 2.25 | 0.75 | 920 | 6.8 † |
| New Jersey | 8,750 | 2.04 | 0.68 | 760 | 8.7 † |
| Georgia | 8,930 | 1.83 | 0.61 | 2,100 | 23.5 |
| District of Columbia | 1,010 | 1.43 | 0.48 | suppressed | n/a |
Source: BLS OEWS, May 2025, occupations 47-2152 (plumbers, pipefitters and steamfitters) and 47-3015 (helpers, pipelayers, plumbers, pipefitters and steamfitters). Helper ratios calculated by The Plumbing Brief. † marks a helper estimate with a relative standard error above 25 percent. Suppressed: BLS did not publish a helper estimate for the state.
Sourced figures
- Plumbers, pipefitters and steamfitters employed nationally, May 2025: 465,840; median annual wage $63,800. Source: BLS OEWS.
- Helpers employed nationally: 44,330; median annual wage $42,360. Source: BLS OEWS.
- Highest concentration: Louisiana, 4.32 per 1,000 jobs (LQ 1.44). Then Maine 4.23, Maryland 4.13, Wyoming 4.05. Source: BLS OEWS.
- Lowest: District of Columbia, 1.43 (LQ 0.48), then Georgia 1.83 and New Jersey 2.04. Source: BLS OEWS.
- States with a location quotient above 1.00: 33 of 51. Source: BLS OEWS.
- Largest plumber workforces: California 47,660, Texas 44,090, Florida 29,260, New York 23,210. Source: BLS OEWS.
- Highest helper ratio among reliable estimates: Louisiana, 24.0 per 100 plumbers; lowest: Wisconsin, 4.4. Source: calculated from BLS OEWS.
- National helper ratio: 9.5 per 100 plumbers. Source: calculated from BLS OEWS.
What we calculated
The biggest coastal markets are thinly plumbed
Formula. Location quotients for the largest coastal states.
Calculation. California 0.87; New York 0.80; Pennsylvania 0.75; New Jersey 0.68.
Finding. All four sit below 0.90; only 8 states and DC are below that line in total. Those labour markets are dominated by office and service employment, which dilutes every trade’s share of jobs. A low quotient is not proof of a shortage, but it does mean fewer plumbers per worker in four of the largest state economies.
Limitations. A location quotient compares shares of jobs, not plumbers per household or per building. States with many workers per household look less plumbed than they are.
Helper ratios vary 5-fold between states
Formula. Helpers (47-3015) divided by plumbers (47-2152) × 100, by state, restricted to helper estimates with an RSE of 25 percent or less.
Calculation. Louisiana 2,010 / 8,360 × 100 = 24.0. Wisconsin 450 / 10,210 × 100 = 4.4.
Finding. Southern states, including Louisiana, Georgia, North Carolina and Texas, run crews with many more helpers per plumber. Under federal occupational coding rules apprentices are counted in the occupation they are training for, plumbers, so the helper count measures a separate tier of unlicensed assistants. High ratios point to a crew model built on helpers rather than to a larger apprentice pipeline.
Limitations. OEWS suppresses helper estimates in several states and many published helper figures carry RSEs above 20 percent. Apprentices are not a separate OEWS occupation.
If you quote one number
- Louisiana has the most plumbers per 1,000 jobs: 4.32.
- The District of Columbia has the fewest: 1.43.
- There are 465,840 plumbers, pipefitters and steamfitters on US payrolls and 44,330 helpers.
- Louisiana employs 24 helpers per 100 plumbers; the national figure is 9.5.
Download the data
All states with employment, RSEs, per-1,000 and location quotient, medians and helper counts. Published under a Creative Commons Attribution 4.0 licence. Attribution: The Plumbing Brief.
Plumber concentration, location quotients and helper ratios by state, May 2025 (CSV)
How this report was built
Methodology
Source. BLS Occupational Employment and Wage Statistics, May 2025 estimates, from the LABSTAT bulk file oe.data.0.Current, retrieved 4 October 2026. Datatypes 01 (employment), 02 (employment RSE), 13 (annual median wage), 16 (employment per 1,000 jobs) and 17 (location quotient) for occupations 47-2152 and 47-3015 in every state and the District of Columbia. Series IDs were built as OEUS + state FIPS + 00000000000 + occupation + datatype and checked against a known series (OEUS060000000000047215216).
Derived figures. Helper ratios and counts of states are calculated by The Plumbing Brief. Rankings of helper ratios exclude helper estimates with an RSE above 25 percent.
Retrieval date. 4 October 2026.
Data limitations
- OEWS counts payroll jobs and excludes the self-employed, a material share of plumbers.
- 47-2152 combines plumbers with pipefitters and steamfitters, who are concentrated in industrial states and on the Gulf Coast. Part of Louisiana’s lead reflects petrochemical pipefitting.
- Under SOC coding rules apprentices are counted in the occupation they are training for (47-2152), not as helpers, so the helper ratio is not an apprenticeship measure.
- May 2025 OEWS estimates pool six survey panels collected over three years.
- State estimates for helpers are suppressed in several states and imprecise in others.
Source quality ranking
Tier 1. US Bureau of Labor Statistics, Occupational Employment and Wage Statistics; Occupational Outlook Handbook: plumbers, pipefitters and steamfitters.
Tier 2. None used. Tier 3. None used.
Excluded. State licensing-board counts, which measure licences held rather than people working, and include inactive and out-of-state licensees.
Summary for reporters
Louisiana has the highest concentration of plumbers, pipefitters and steamfitters in the US workforce, 4.32 per 1,000 jobs, and the District of Columbia the lowest at 1.43, according to Bureau of Labor Statistics occupational estimates for May 2025. Plumbers are more concentrated than the national average in 33 of 51 states and DC, while California, New York, Pennsylvania and New Jersey sit well below it. An analysis by The Plumbing Brief found that the number of plumber helpers per 100 plumbers ranges from 24.0 in Louisiana to 4.4 in Wisconsin, against 9.5 nationally.
Angles this supports
- The most plumbed state in America is Louisiana
- California and New York have the fewest plumbers per worker
- The South runs on plumber helpers
- Plumbers per 1,000 jobs: the state map
- Why the biggest markets have the thinnest plumbing workforce
Questions this answers
Which state has the most plumbers? By headcount, California with 47,660. By concentration, Louisiana with 4.32 per 1,000 jobs.
Which state has the fewest plumbers relative to its workforce? The District of Columbia, 1.43 per 1,000 jobs, then Georgia and New Jersey.
What is a location quotient? The share of a state’s jobs in an occupation divided by the national share. Above 1.00 means more concentrated than the US average.
How many plumber helpers are there? 44,330 nationally in May 2025, 9.5 for every 100 plumbers.
Where are plumber helpers most common? In the South. Louisiana has 24.0 helpers per 100 plumbers, Georgia 23.5.
Does this count self-employed plumbers? No. OEWS covers payroll employment only.
How to cite this report
The Plumbing Brief, “Where Plumbers Are Concentrated: Plumbers per 1,000 Jobs and Helper Ratios by State”, https://theplumbingbrief.com/where-plumbers-are-concentrated/, accessed [date].
Last reviewed: 2026-10-04.
