USPS

Package tracking, ZIP code lookup and postage estimates

USPS provides latest available package tracking, standardized U.S. addresses with ZIP+4, recommended cities for five-digit ZIP Codes, and estimated domestic postage and delivery dates.

Estimate postage

Estimate domestic USPS Post Office retail postage by ZIP Codes, weight, shape, and mailing date. Shows available ordinary services or flat-rate packaging options; a zero-pound letter with no extra ounces is treated as a one-ounce letter. Media Mail is excluded because eligibility depends on contents. Delivery dates are estimates, and prices exclude optional paid extras.

Your information

Weight (lb)

Weight in pounds, for example 2; enter 0 for a letter under a pound.

Weight OzOptional

Additional ounces beyond the whole pounds, for example 8.

From ZIP

Five-digit ZIP Code where the item is mailed, for example 10001.

Package TypeOptional

Mailpiece or USPS flat-rate packaging type, for example package.

To ZIP

Five-digit destination ZIP Code, for example 94105.

More options

Width inOptional

Package width in inches, for example 6; defaults to a small box.

Height inOptional

Package height in inches, for example 4; defaults to a small box.

Length inOptional

Package length in inches, for example 8; defaults to a small box.

Ship DateOptional

Planned mailing date, for example 2026-10-01; defaults to today.

1 credit per completed run

The same inputs also work from your code or an AI assistant. See For developers.

Example results

First-Class Mail Stamped Letter

Lowest price$0.82Sat, Oct 3

Available services

Postage: $0.82
Estimated delivery: Oct 3, 2026
Delivery estimate: Sat, Oct 3

Included extras

No included extras

View USPS details

About the USPS tool

USPS returns package status and delivery details from a tracking number.

Get zip code standardizes a US street address; Get city for zip finds city details from a ZIP Code.

Estimate postage compares domestic retail options using ZIP Codes, weight, package shape, and mailing date.

Built from usps.com, tools.usps.com and postcalc.usps.com. Last checked Sep 29, 2026.

Actions

Estimate postage

1 credit

Uses postcalc.usps.com.

What you provide

Field	Type	Required	Description
Width in`width_in`	Number	Optional	Package width in inches, for example 6; defaults to a small box.
Height in`height_in`	Number	Optional	Package height in inches, for example 4; defaults to a small box.
Length in`length_in`	Number	Optional	Package length in inches, for example 8; defaults to a small box.
Ship Date`ship_date`	Date	Optional	Planned mailing date, for example 2026-10-01; defaults to today.
Weight (lb)`weight_lb`	Number	Required	Weight in pounds, for example 2; enter 0 for a letter under a pound.Example: 0
Weight Oz`weight_oz`	Number	Optional	Additional ounces beyond the whole pounds, for example 8.Example: 1
Origin Zip`origin_zip`	Text	Required	Five-digit ZIP Code where the item is mailed, for example 10001.Example: 10001
Package Type`package_type`	Text	Optional	Mailpiece or USPS flat-rate packaging type, for example package.Example: Letter
Destination Zip`destination_zip`	Text	Required	Five-digit destination ZIP Code, for example 94105.Example: 94105

What you get

Field	Type	Description
Note`note`	Text
Services`services`	List	Available retail postage options, cheapest first.
Currency`services[].currency`	Text	Example: USD
Page Link`services[].page_link`	Text	Example: https://postcalc.usps.com/Calculator/ExtraServices?country=0&ccode=US&oz=10001&…
Retail Price`services[].retail_price`	Number	Example: 0.82
Service Name`services[].service_name`	Text	Example: First-Class Mail Stamped Letter
Included Extras`services[].included_extras`	List
Expected Delivery Date`services[].expected_delivery_date`	Date	Example: 2026-10-03
Estimated Delivery Time`services[].estimated_delivery_time`	Text	Example: Sat, Oct 3

Example result

For Weight (lb): 0, Weight Oz: 1, Origin Zip: 10001, Package Type: Letter, Destination Zip: 94105

JSON

{
  "note": null,
  "services": [
    {
      "currency": "USD",
      "page_link": "https://postcalc.usps.com/Calculator/ExtraServices?country=0&ccode=US&oz=10001&omil=False&dz=94105&dmil=False&retail=False&mdt=9/28/2026&mdz=8:00 AM&m=1&hscode=False&p=0&o=1&rect=True&l=0&h=0&w=0&g=0&…",
      "retail_price": 0.82,
      "service_name": "First-Class Mail Stamped Letter",
      "included_extras": [],
      "expected_delivery_date": "2026-10-03",
      "estimated_delivery_time": "Sat, Oct 3"
    },
    {
      "currency": "USD",
      "page_link": "https://postcalc.usps.com/Calculator/ExtraServices?country=0&ccode=US&oz=10001&omil=False&dz=94105&dmil=False&retail=False&mdt=9/28/2026&mdz=8:00 AM&m=1&hscode=False&p=0&o=1&rect=True&l=0&h=0&w=0&g=0&…",
      "retail_price": 16.95,
      "service_name": "Priority Mail",
      "included_extras": [
        "USPS Tracking",
        "Insurance up to $100"
      ],
      "expected_delivery_date": "2026-10-01",
      "estimated_delivery_time": "Thu, Oct 1"
    },
    {
      "currency": "USD",
      "page_link": "https://postcalc.usps.com/Calculator/ExtraServices?country=0&ccode=US&oz=10001&omil=False&dz=94105&dmil=False&retail=False&mdt=9/28/2026&mdz=8:00 AM&m=1&hscode=False&p=0&o=1&rect=True&l=0&h=0&w=0&g=0&…",
      "retail_price": 53.35,
      "service_name": "Priority Mail Express",
      "included_extras": [
        "USPS Tracking",
        "Insurance up to $100"
      ],
      "expected_delivery_date": "2026-09-29",
      "estimated_delivery_time": "Tue, Sep 29 by 6:00 PM"
    }
  ]
}

Get city for zip

1 credit

Find the USPS recommended city and state, other recognized city names, names to avoid, and ZIP type for a five-digit US ZIP Code. ZIP+4 is reduced to its first five digits.

Uses tools.usps.com.

What you provide

Field	Type	Required	Description
Zip Code`zip_code`	Text	Required	Five-digit ZIP Code or ZIP+4, for example 10001 or 10001-1234.Example: 90210-1234

What you get

Field	Type	Description
Page URL`page_url`	Text	USPS Cities by ZIP Code page.Example: https://tools.usps.com/zip-code-lookup.htm?citybyzipcode
Zip Code`zip_code`	Text	The five-digit ZIP Code.Example: 90210
Zip Type`zip_type`	Text	ZIP classification when provided, such as PO Box only or Military.Example: Standard
State Code`state_code`	Text	Two-letter state or territory abbreviation.Example: CA
State Name`state_name`	Text	Full state or territory name.Example: California
Cities to Avoid`cities_to_avoid`	List	City names USPS says to avoid for this ZIP Code.
Recommended City`recommended_city`	Text	USPS recommended city name.Example: BEVERLY HILLS
Other Accepted Cities`other_accepted_cities`	List	Other city names USPS recognizes for addresses in this ZIP Code.

Example result

For Zip Code: 90210-1234

JSON

{
  "page_url": "https://tools.usps.com/zip-code-lookup.htm?citybyzipcode",
  "zip_code": "90210",
  "zip_type": "Standard",
  "state_code": "CA",
  "state_name": "California",
  "cities_to_avoid": [],
  "recommended_city": "BEVERLY HILLS",
  "other_accepted_cities": []
}

Get zip code

1 credit

Standardize a US street address with USPS and find its ZIP+4. When several addresses match, the main address is the first result and all choices appear in matches. A ZIP Code result does not confirm who lives at an address.

Uses tools.usps.com.

What you provide

Field	Type	Required	Description
City`city`	Text	Required	City name, such as Washington.Example: Washington
State`state`	Text	Required	State name or two-letter code, such as District of Columbia or DC.Example: DC
Zip Code`zip_code`	Text	Optional	ZIP Code if known, such as 20500.Example: 10118
Street Address`street_address`	Text	Required	Street number and name, such as 1600 Pennsylvania Ave NW.Example: 1600 Pennsylvania Ave NW
Apartment or Suite`apartment_or_suite`	Text	Optional	Unit or suite, such as Apt 4B.Example: Ste 4750

What you get

Field	Type	Description
City`city`	Text	USPS-formatted city.Example: WASHINGTON
Note`note`	Text	What to check when no address is recognized.Example: Check the street number, street name, city, state, ZIP Code, and apartment or…
State`state`	Text	Two-letter USPS state abbreviation.Example: DC
County`county`	Text	USPS county name.Example: DISTRICT OF COLUMBIA
Matches`matches`	List	All USPS address choices when multiple results are found; otherwise empty.
City`matches[].city`	Text	USPS-formatted city.Example: NEW YORK
State`matches[].state`	Text	Two-letter USPS state abbreviation.Example: NY
County`matches[].county`	Text	USPS county name.Example: NEW YORK
Page URL`matches[].page_url`	Text	USPS lookup page for this address.Example: https://tools.usps.com/zip-code-lookup.htm?byaddress
Zip Code`matches[].zip_code`	Text	Five-digit ZIP Code.Example: 10118
Zip Plus 4`matches[].zip_plus_4`	Text	Nine-digit ZIP+4 in five-plus-four format.Example: 10118-0110
Street Line`matches[].street_line`	Text	USPS-formatted street address, including unit when present.Example: 350 5TH AVE
Carrier Route`matches[].carrier_route`	Text	USPS mail carrier route.Example: C082
Delivery Point`matches[].delivery_point`	Text	USPS delivery point code.Example: 99
Page URL`page_url`	Text	USPS lookup page for this address.Example: https://tools.usps.com/zip-code-lookup.htm?byaddress
Zip Code`zip_code`	Text	Five-digit ZIP Code.Example: 20500
Recognized`recognized`	Text	Whether USPS returned an address match.Example: Yes
Zip Plus 4`zip_plus_4`	Text	Nine-digit ZIP+4 in five-plus-four format.Example: 20500-0005
Street Line`street_line`	Text	USPS-formatted street address, including unit when present.Example: 1600 PENNSYLVANIA AVE NW
Carrier Route`carrier_route`	Text	USPS mail carrier route.Example: C000
Delivery Point`delivery_point`	Text	USPS delivery point code.Example: 00

Example result

For City: Washington, State: DC, Street Address: 1600 Pennsylvania Ave NW

JSON

{
  "city": "WASHINGTON",
  "note": null,
  "state": "DC",
  "county": "DISTRICT OF COLUMBIA",
  "matches": [],
  "page_url": "https://tools.usps.com/zip-code-lookup.htm?byaddress",
  "zip_code": "20500",
  "recognized": "yes",
  "zip_plus_4": "20500-0005",
  "street_line": "1600 PENNSYLVANIA AVE NW",
  "carrier_route": "C000",
  "delivery_point": "00"
}

Track package

1 credit

Track a USPS package or letter by its tracking number. Returns the latest status, delivery details, and available tracking history; unavailable or ambiguous numbers may need additional details on USPS.

Uses tools.usps.com.

What you provide

Field	Type	Required	Description
Tracking Number`tracking_number`	Text	Required	Tracking number on the receipt or label, such as 9400 1000 0000 0000 0000 00 or EC123456789US.Example: 9489 0178 9820 3036 9522 01

What you get

Field	Type	Description
Events`events`	List
Event`events[].event`	Text	Example: Delivered, Left with Individual
Location`events[].location`	Text	Example: LAS VEGAS, NV 89119
Date Time`events[].date_time`	Text	Local date and time of the event, ISO 8601 with UTC offset when the location can be resolved.Example: 2026-01-31T14:21:00-08:00
Status`status`	Text	Example: Delivered, Left with Individual
Delivered At`delivered_at`	Text	Example: 2026-01-31T14:21:00-08:00
Mail Service`mail_service`	Text	Example: First-Class Mail®
Last Location`last_location`	Text	Example: LAS VEGAS, NV 89119
Tracking Link`tracking_link`	Text	Example: https://tools.usps.com/go/TrackConfirmAction?tLabels=9489017898203036952201
Last Event Time`last_event_time`	Text	Example: 2026-01-31T14:21:00-08:00
Tracking Number`tracking_number`	Text	Example: 9489017898203036952201
Expected Delivery Date`expected_delivery_date`	Text
Expected Delivery Time Window`expected_delivery_time_window`	Text

Example result

For Tracking Number: 9489 0178 9820 3036 9522 01

JSON

{
  "events": [
    {
      "event": "Delivered, Left with Individual",
      "location": "LAS VEGAS, NV 89119",
      "date_time": "2026-01-31T14:21:00-08:00"
    },
    {
      "event": "Arrived at USPS Facility",
      "location": "LAS VEGAS NV DISTRIBUTION CENTER",
      "date_time": "2026-01-30T08:29:00-08:00"
    },
    {
      "event": "Arrived at USPS Facility",
      "location": "RENO NV DISTRIBUTION CENTER",
      "date_time": "2026-01-29T09:30:00-08:00"
    }
  ],
  "status": "Delivered, Left with Individual",
  "delivered_at": "2026-01-31T14:21:00-08:00",
  "mail_service": "First-Class Mail®",
  "last_location": "LAS VEGAS, NV 89119",
  "tracking_link": "https://tools.usps.com/go/TrackConfirmAction?tLabels=9489017898203036952201",
  "last_event_time": "2026-01-31T14:21:00-08:00",
  "tracking_number": "9489017898203036952201",
  "expected_delivery_date": null,
  "expected_delivery_time_window": null
}

For developers

Call it from your code with one request. Change the values in input to run it on new data. To get an API key, open Developers at the bottom of Studio, turn on Developer mode and go to API keys.

cURL

curl 'https://api.fous.com/v1/query' \
  --fail-with-body --silent --show-error --max-time 180 \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H 'Content-Type: application/json' \
  --data-raw '{
  "api": "@usps",
  "visibility": "public",
  "operation": "estimate_postage",
  "version": 1,
  "input": {
    "weight_lb": 0,
    "weight_oz": 1,
    "origin_zip": "10001",
    "package_type": "letter",
    "destination_zip": "94105"
  },
  "response": {
    "format": "json"
  }
}'

What you can do with it

Check package status and delivery details using a tracking number.
Standardize street addresses and find ZIP+4 codes.
Find recommended and accepted city names for a ZIP Code.
Compare domestic retail postage options by price and service.
Estimate postage for a planned mailing date and package size.

Questions about USPS

Can I run it with my own inputs?

Yes. Change the inputs in Studio and press Run, or send new inputs from your code, or ask a connected AI assistant.

Can I call this USPS tool as an API?

Yes. Send a POST request to /v1/query with your Fous API key and the inputs, and get JSON back.

How much does it cost?

Each completed run costs 1 credit. Failed runs without a completed receipt are free; completed work can remain charged if delivery is interrupted. With pay as you go, a credit costs 1¢. Monthly plans cost less per credit.

Do I need a USPS account?

No. You only need a Fous account.

How current is the data?

Fous gets the data from usps.com when you run it. Some results are reused for up to 24 hours, and results that use your account or key are never reused. It was last verified on Sep 29, 2026.