In India, people often use the words completed age and running age. They are not the same.
The Age Difference Calculator gives the exact gap between two birth dates. For a form, you must also check which type of age the form asks for.
What is completed age?
Completed age means the number of full years a person has finished.
Example: Riya was born on 10 October 2000. On 1 September 2026, she has not reached her birthday for that year. Her completed age is 25 years.
Completed age is the number most official forms use when they ask for “age in completed years”.
What is running age?
Running age means the year of life a person is currently living.
In the example above, Riya has completed 25 years and is living her 26th year. People may say her running age is 26.
Running age is common in normal conversation, but it may not be accepted on an official form.
A simple way to say it is: after completing 25 years, the 26th year of life is running. This does not normally mean the person is already 26 years old.
What is exact age?
Exact age includes years, months and days.
For example:
25 years, 10 months and 22 days
This gives more detail than completed or running age.
Example before, on and after a birthday
Suppose Aman was born on 15 November 2001.
- On 14 November 2026, his completed age is 24.
- On 15 November 2026, he completes 25 years.
- On 16 November 2026, his completed age is still 25 and his 26th year is running.
The birthday changes the completed age. The running year changes at the same point but is usually one number higher.
What do common running-age numbers mean?
The rule is the same at every age: the running age is usually one more than the completed age.
- 18 running age usually means 17 full years are completed and the 18th year has started.
- 20 running age usually means 19 full years are completed and the 20th year has started.
- 25 running age usually means 24 full years are completed and the 25th year has started.
This is everyday wording, not a replacement for the wording on an official form. If a notice says “completed years,” write the completed age instead.
What does “age as on” mean?
“Age as on” means age on a stated cut-off date. It may not mean age today or age on the application date.
For example, a notice may ask for age as on 1 January 2027. Compare the date of birth with 1 January 2027, even if you fill in the form several months earlier.
Read the complete notice because different organisations can set different rules, age limits and relaxations.
Which age should you write on a form?
Read the form carefully.
- If it asks for completed years, write only the full years finished.
- If it gives a cut-off date, calculate age on that date.
- If it asks for date of birth, enter the date exactly as shown on your document.
- If it asks for age today, use today as the comparison date.
- If it uses an age range, check whether both end limits are included.
For exams, jobs, insurance or government work, always follow the official notice. Do not guess from normal conversation.
Common mistakes on Indian forms
- Writing running age when the form asks for completed years.
- Calculating from today instead of the given cut-off date.
- Reading 06/09/2000 as 9 June instead of 6 September.
- Subtracting only the year numbers without checking the birthday.
- Assuming that an online calculator decides eligibility.
An age calculator can help with the date maths. It cannot apply category relaxation, document rules or special conditions unless those rules are entered and checked separately.
Quick rule to remember
Completed age is the number of full years already lived. Running age usually names the year of life now underway. Exact age adds the remaining months and days.
When a form gives its own definition, follow that definition instead of the everyday meaning. To compare two birth dates in years, months and days, use the Age Difference Calculator. You can also read why the completed-age difference can appear to change between birthdays.
Use the Age Difference Calculator