Century Calculator
Determine which century and millennium a year belongs to. Shows the ordinal century, millennium, decade, era (AD/BC), and date ranges.
How to Use Century Calculator
The Century Calculator determines which century and millennium any given year belongs to. Enter a year (positive for AD/CE, negative for BC/BCE) and instantly see the ordinal century (e.g., 21st century), the millennium (e.g., 3rd millennium), the decade, the era designation, and the exact year ranges for both the century and millennium. Handles edge cases correctly — year 2000 is the 20th century, year 2001 starts the 21st. Useful for history students, trivia enthusiasts, writers researching time periods, and anyone curious about chronological classification.
Step-by-Step Instructions
- Enter a year (use negative for BC)
- Click Calculate
- View the century, millennium, and decade
- See the exact year ranges for each period
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