Data sources and methodology
Last updated: 20 September 2026
Every directory on this site is generated from public datasets. This page lists them and explains their limits.
Datasets
| Section | Source | Terms |
|---|---|---|
| US ZIP codes, Canadian postal areas, world postal codes | GeoNames postal code data | Creative Commons Attribution licence. Credit: GeoNames. |
| North American area codes | North American Numbering Plan Administrator (NANPA) NPA database | Published by NANPA for public download. |
| Country calling codes and example number formats | Google libphonenumber metadata | Apache License 2.0. |
| Nutrition facts | USDA FoodData Central | Published by the US Department of Agriculture. See the FoodData Central site for its current terms. |
| US bank branch locations and bank websites | FDIC BankFind Suite (institutions and locations) | Published by the Federal Deposit Insurance Corporation for public use. See the FDIC site for its current terms. |
| Unit converters | Exact unit definitions (US customary and SI) | Not applicable. |
Methodology
- Counts and ranges on a page are calculated from the list on that page.
- Duplicates are removed, so each ZIP code appears once.
- Canadian postal codes: full six-character codes are protected by Canada Post copyright, so we publish only the three-character forward sortation areas.
- Bank locations: we keep active FDIC-insured institutions and their full-service offices. Loan offices, administrative offices, closed branches and other limited-service sites are left out. Credit unions are not included. The FDIC data contains no phone numbers or opening hours, so we publish none.
- Postal code coverage depends on which countries publish their codes under an open licence, so some countries are missing.
- Nutrition values are shown per 100 g as published by the USDA. Per-serving values are calculated from the serving weight in the database. Calorie shares by macronutrient use the standard factors of 4 kcal per gram for protein and carbohydrate and 9 kcal per gram for fat.
How often we update
We refresh datasets from their sources on a regular schedule and rebuild the site. Postal codes and area codes change over time, so a list may lag behind the official source. For mailing or dialling decisions that matter, check the official provider.
Attribution
Postal code data © GeoNames, used under a Creative Commons Attribution licence. Contains data published by the US Department of Agriculture and the North American Numbering Plan Administrator.
Found a problem? Tell us.