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What is an Age Calculator?
An age calculator is a tool that determines your exact age in years, months, and days. It calculates your age based on the number of full years, months, and days between your birthdate and a specific date, following the Western system of age calculation, which counts the time from one birthday to the next.
How to Calculate Age?
Yes, there are various cultural methods for calculating age, but the Western style is the most commonly used standard. It calculates age by counting the full years, months, and days from one birthday to the next. This approach is widely recognized and used in many contexts, including official documents and age-related calculations.
How to calculate age based on the Western system of age calculation
The Western style of age calculation is straightforward: you count the time from one birthday to the next to determine your age. For example:
- A person born on August 4, 2022, will be one year old on August 4, 2023.
- Someone born on January 16, 2002, will be one year old on January 16, 2003. As of October 23, 2022, they would be 20 years, 9 months, and 7 days old.
A simple trick to calculate your age is to subtract your date of birth from today’s date. This method gives you a quick estimate of your exact age in years, months, and days.
For example, if you are date of birth is 17 February 2001, you can calculate your age as:
| Date Today | 2022 | 09 (September) | 23 |
| Date Of Birth | 2001 | 02 (February) | 17 |
| (subtract) | – | – | – |
| Your Age | 21 Years | 7 Months | 6 days |
In case your birthday cannot be directly subtracted from today‘s date, then the calculation is slightly different. For example if your date of birth is on 27 September 2001, then you can calculate your age as follows:
| Date Today | 2022 | 09 (September) | 23 |
| Date Of Birth | 2001 | 09 (September) | 26 |
| (subtract) | – | – | – |
| Net | 21 Years | 0 Months | -3 days |
| How to Calculate | 21 Years-1 Year | 12 Months-(0+1) Month=12 Months-1 Month | 30 days -3 days |
| Your Actual Age | 20 Years | 11 Months | 27 days |
The -3 in the date indicates that you are 3 days younger than 21 years, or in other words, you are 20 years 11 months 27 days old.
Similarly, if you were born on 15 November 2022, then you age as of today will be:
| Date Today | 2022 | 11 (September) | 23 |
| Date Of Birth | 2001 | 11 (November) | 15 |
| (subtract) | – | – | – |
| Net | 21 Years | -2 Months | 8 days |
| How to Calculate | 21 Years-1 Year | 12 Months – 2 Month | 8 days |
| Your Actual Age | 20 Years | 10 Months | 8 days |
If your date of birth is 26, 2001, then your age will be calculated as:
| Date Today | 2020 | 09 (September) | 23 |
| Date Of Birth | 2001 | 09 (September) | 26 |
| (subtract) | – | – | – |
| Net | 21 Years | 0 Months | -3 days |
| How to Calculate | 21 Years-1 Year | 12 Months-(0+1) Month=12 Months-1 Month | 30 days -3 days |
| Your Actual Age | 20 Years | 11 Months | 27 days |
In the same manner, if you wish to calculate your age as of a particular date other than the date of that day, then you can do it as follows:
| Date Till Which Age is to be Calculated | 2022 | 09 (September) | 28 |
| Date Of Birth | 2001 | 09 (February) | 17 |
| (subtract) | – | – | – |
| Your Age | 21 Years | 07 Months | 11 days |
So your age as of 28 September 2022 will be 21 years, 7 months and 11 days.
Calculating Age in Days
The calculation of your age in terms of total number of days is also very simple. You just have to convert all the years and the months into days and add them together.
To calculate the same, you need to remember two simple calculations:
- 1 Year= 365 Days
- 1 Month= 30 Months
So, to calculate your age in total number of days, convert your age to total days. For instance if you are 21 years 3 months and 5 days old, then your age in total number of days will be calculated as follows:
(21 x 365) + (3 x 30) + 5
= 7665 + 90 + 5
= 7760 days
Similarly, if you are 16 years, 9 months and 12 days old, then your age in days will be:
(16 x 365) + (9 x 30) + 12
=5840 + 270 + 12
=6122 days
The Longest Confusion: Running Age or Completed Age?
When calculating age, people often get confused between “completed age” and “running age.”
Completed age is the number of full years you’ve lived since your last birthday. For example, if you were born on August 8, 2002, and today is September 25, 2023, your completed age would be 21 years because you’ve had 21 full birthdays.
Running age, on the other hand, is how old you are in the current year of life. So, using the same example, even though you’ve completed 21 years, you are in your 22nd year of life, so your running age is 22.
In short, your completed age counts full years, while your running age counts the current year you’re living through.
Which One is the Correct Way: Completed Age or Running Age?
There’s no one-size-fits-all answer to how age should be expressed. Some people use their running age in casual conversations, while others prefer their completed age. So, when someone says they’re ‘x’ years old, it could be referring to either their completed age or their running age.
For formal situations, the most precise way to state your age is to specify it in terms of years, months, and days as of a specific date.
How Many Days Until a Birthday?
If you are trying to calculate the number of days till your next birthday, you can simply subtract the date (today) from your coming birthday.
For example if you were born on 23 November 2000 and today is 23 September 2022, then you can calculate your birthday as follows:
| Coming Birthday | 2022 | 11 (November) | 23 |
| Date Today | 2001 | 09 (September) | 23 |
| (subtract) | – | – | – |
| Your Age | 0 Years | 02 Months | 0 days |
This means there are 2 months left for your birthday!
Format of the Date
There are various patterns of writing the date and it can be confusing to some of those who are not aware of it.
- The American pattern of writing the date is MM/DD/YYYY.
- The British pattern of writing the date starts from the day, then the month and lastly the year, i.e. DD/MM/YYYY.
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FAQs - Frequently Asked Questions
An age calculator finds your exact age in years, months, and days from your birthdate to today, using the Western system of counting time from one birthday to the next.
To calculate completed age, count the full years since your birthdate. For example, if someone was born on January 28, 2001, their completed age on September 23, 2022, would be 21 years.
In informal settings, using either completed age or running age is fine. However, for formal interactions, it’s best to provide your full age in years, months, and days from your birthdate to the specific date in question.
It does not make much difference as to whether you are calculating your age in terms of DD/MM/YYYY or MM/DD/YYYY format because in either case, it is your date of birth that is of importance and used for calculating your age. While writing your age, it is written in the format- number of years, number of months and lastly the number of days.