Regional Statistics
Population in Ostrołęka 2018
In 2018, Ostrołęka county ranked 301 of 380 Polish counties. Population shrank by 655 residents -1.24% between 2013-2018, at 52,262.
Among 339 declining counties, in the bottom 10% for rate of decline (mildest loss). Within Masovian voivodeship, ranked 33 of 42 counties.
Based on 31 years of official GUS statistics for Ostrołęka county and its 1 municipality within Masovian voivodeship.
Popular Cities in Poland
You may also be interested in
Contact Information for Ostrołęka
Updated 52 days ago
Top tools
PESEL Number Checker
Enter a PESEL number to extract the birth date, gender, and verify the check digit. Works as both a PESEL checker and validator.
NIP Generator
Generate valid Polish NIP (VAT / tax ID) numbers with correct checksums for software testing.
Polish IBAN Generator
Generate a valid Polish IBAN from a bank code and account number. See the 28-character PL IBAN format with a real example.
Top articles
How to Pay Tax on Rental Income in Poland
Step-by-step guide to paying tax on rental income in Poland: ryczałt rates, registration, monthly payments via mikrorachunek, and PIT-28 filing.
10 min readNIP Number in Poland: How to Find, Check, and Validate It
What is a NIP number in Poland? Learn how to find your own NIP, check a company's tax ID, and validate any Polish NIP online.
7 min readHow to Get a PESEL for Your Child Born Abroad or Newborn in Poland
How to get a PESEL for your child born outside Poland or as a newborn. Required documents, which office to visit, and what to expect.
7 min readLet's build Poland.gg together
Join our Discord community. Get early access, shape the roadmap, and connect with data people across Poland.
Dashboard and business tools go public in 2027 — early supporters access them first and keep their discount on everything.
Get up to 90% off — forever
The longer you stay, the less you pay. 9% off per month, stacking up to 90%. The 100 longest supporters get free access for life.
© 2026 Poland.gg