The rule
Minguo year = Western year − 1911. The Minguo era starts in 1912, the founding of the Republic of China, so 1912 is year 1 (民國元年) and 2026 is Minguo 115.
Where you'll see it
Taiwan uses Minguo years on ID cards, government forms, uniform invoices, bank documents and product expiry dates — often in a short form like 115/10/20. If a "best before" date looks like it's from the distant past, it's probably a Minguo date.
Frequently asked questions
What is Minguo 115?
2026.
How are years before 1912 written?
As years 'before Minguo' (民國前): 1911 is 民國前1年.
Is this the same as the Juche calendar?
No. North Korea's Juche calendar also starts in 1912 but is a different system; this tool is for Taiwan's Minguo calendar.