Lunar Age Calculator
Find your lunar age, the East Asian reckoning where you start at one.
PregnancyScience-backed formula
Enter your details
Fill in the fields, then calculate
Please choose a date.
Awaiting Data
Enter your details and tap Calculate to see your results appear here.
0
ResultYour result appears here.
What it measures
In several East Asian traditions, a baby is one year old at birth and gains a year at each new year. This lunar or nominal age usually runs one to two years ahead of Western age.
Key dates line up into an easy week by week timeline.
It is also used with the Chinese gender chart.
How to use this calculator
- Enter your date of birth.
- Tap Calculate for your lunar age.
The formula used
Lunar age = current year − birth year + 1
- birth year
- The year you were born.
- current year
- This year.
Understanding Your Results
Lunar age
Nominal count
Starts at one at birth.
Western age
Completed years
For comparison.
Difference
1 to 2 years
Lunar runs ahead.
Tips to Improve
- Use lunar age with the gender chart.
- It differs from your legal age.
- One year is added at each new year.
- Pair with the chronological age tool.
Frequently Asked Questions
Tradition counts the time in the womb as the first year.
No. Most countries use Western age legally.
It is a simple nominal count, not to the day.
Scientific References
- Korea Legislation Research Institute. (2023). Age counting reform.
- Aylin, P. (2002). Traditional age reckoning in East Asia. Population Studies.