91731 ZIP Code, El Monte, CA

91731 is a ZIP code in El Monte, California in Los Angeles County. It covers 3.8 square miles of land. The closest ZIP codes are 91732, 91780 and 91733. 27,620 people live here in 8,293 households. At about 7,278 people per square mile it is built up to city-neighborhood density, and most households rent (40% own). Median household income is $62,215, well below the California median of $99,122.

Quick facts

Key figures

MeasureValue
Residents27,620
Households8,293
Median household income$62,215
Income per person$24,216
Median age36.6
Homeowners39.6%
Median home value$635,600
Median rent$1,669
Bachelor's degree or higher15.2%
Average commute (minutes)29.3
Households with kids under 1835.0%
Moved in the past year4.4%
Below the poverty line17.8%
Broadband internet87.6%
Speak a non-English language at home84.0%

Household income

% of householdsValue
<$10K4.9%
$10–15K5.4%
$15–25K10.0%
$25–35K10.0%
$35–50K11.1%
$50–75K17.1%
$75–100K12.4%
$100–150K15.5%
$150–200K7.7%
$200K+5.8%

Age

% of all residentsValue
<1012.2%
10–1913.2%
20–246.5%
25–3414.7%
35–4413.5%
45–5411.2%
55–6411.2%
65–749.6%
75+7.9%

Tenure

% of housing unitsValue
Owned, with mortgage20.0%
Owned outright18.6%
Rented57.3%
Vacant4.1%

Type of building

% of housing unitsValue
Detached house48.5%
Townhome6.3%
2–4 units6.5%
5–19 units9.6%
20+ units24.4%
Mobile / other4.8%

Businesses in 91731

1,102 business establishments with 15,623 employees (ZIP Codes Business Patterns 2023).

EDDM carrier routes

91731 has 14 USPS carrier routes with 8,465 residential and 1,782 business mailboxes. Open the EDDM route map.

Carrier routes in 91731

91731 has 14 USPS carrier routes (14 city (C)) with 8,465 residential and 1,782 business mailboxes. Routes range from 252 homes (C002) to 866 homes (C012); the median route has 654 homes. The Census counted 8,293 households in 91731 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.

Homes per routeRoutes
1–2490
250–4993
500–7498
750–9993
1,000–1,4990
1,500+0

Best routes in 91731 for…

Most businesses

For B2B offers: office supplies, cleaning, IT, catering and commercial services.

  1. Route C012 — USPS business mailboxes 276, 866 homes
  2. Route C001 — USPS business mailboxes 253, 758 homes
  3. Route C002 — USPS business mailboxes 231, 252 homes
  4. Route C014 — USPS business mailboxes 183, 275 homes
  5. Route C021 — USPS business mailboxes 169, 718 homes

Select these 5 routes on the route map

Every carrier route in 91731

RouteTypeHomesBusinessesEst. median incomeEst. ownersEst. families with kidsEst. moved in past year
C001City758253$24,130———
C002City252231$58,174———
C003City64527$55,251———
C004City70314$48,174———
C005City51821$78,609———
C006City66387$39,396———
C007City61266$53,421———
C011City519155$98,136———
C012City866276$48,174———
C013City484139$76,087———
C014City275183$98,136———
C015City666150$98,136———
C016City78611$57,304———
C021City718169$48,174———

Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 91731 on the EDDM route map.

How route demographics are estimated

Mailbox counts come from USPS; demographics are estimates

The number of homes and businesses on each carrier route is the current USPS EDDM count. The Census Bureau does not publish figures for carrier routes, so income, homeownership, ages, families, movers and housing age on a route are EDDM2GO estimates built from Census block groups (neighborhood areas of roughly 600 to 3,000 people).

How a route gets its figures: the block-group length-share method

We trace each route's streets every 25 meters and record which block group each stretch falls in. The route's homes are spread along its streets in proportion to length, so a route with 60% of its street length in one block group is assumed to have 60% of its homes there. Each block group then contributes its Census counts in proportion to the share of its housing units that sit on the route (capped at the whole block group). Medians are recalculated from the combined income, home-value and age brackets, the way the Census Bureau computes them, not averaged.

Margins of error

Census survey figures carry a margin of error at 90% confidence; we carry it through the calculation and show it as ±. Our margins treat the route-to-block-group split as exact, so the real uncertainty is larger. Routes with fewer than 100 estimated households, large margins, or streets we could not place are flagged.

Different years

USPS mailbox counts are current. Census figures are 5-year averages for 2020–2024, so a new subdivision may have more homes on the route today than the Census counted. Use the route figures to compare routes with each other, not as an exact head count.

Why some routes show identical figures

Two routes that run through the same block group get the same percentages and medians, because the Census publishes one set of figures for the whole block group. Their mailbox counts still differ, and those are exact.

Route and mailbox counts: USPS EDDM route data. Route demographics: EDDM2GO estimates from U.S. Census Bureau American Community Survey 5-year block-group data (2020–2024) and 2024 cartographic block-group boundaries. This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.

Nearby ZIP codes

Areas that include 91731

Mail every home in 91731

Route counts on this page price as Full Service 6.5 × 9 postcards: we print, bundle by carrier route and hand the mailing to USPS. Prefer to take it to the Post Office yourself? Print only costs less and you pay postage at drop-off.

EDDM guides

ZIP code statistics describe the Census ZIP Code Tabulation Area (ZCTA) 91731, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.

Frequently asked questions

What city is 91731 in?
91731 is a El Monte, CA mailing address. By land area, 100% lies inside El Monte.
What county is 91731 in?
91731 is in Los Angeles County.
What is the population of 91731?
About 27,620 people (±1,744), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 28,197.
What is the median household income in 91731?
$62,215 (±$4,336), compared with $99,122 for California as a whole. Half the households in the ZIP code earn more and half earn less.
How many carrier routes and mailboxes are in 91731?
14 USPS carrier routes with 8,465 residential and 1,782 business mailboxes (10,246 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
What ZIP codes are near 91731?
The closest, measured center to center: 91732 (1.7 mi, El Monte), 91780 (1.7 mi, Temple City), 91733 (2.3 mi, South El Monte), 91770 (2.4 mi, Rosemead), 91776 (3 mi, San Gabriel) and 91007 (3.4 mi, Arcadia).

This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.