Enter the start date and the number of years into the calculator to determine the anniversary date; this calculator can also evaluate any of the variables given the others are known.

Anniversary Formula

The following formula is used to calculate the anniversary date:

AD = SD + Y


  • AD is the anniversary date
  • SD is the start date
  • Y is the number of years

To calculate the anniversary date, add the number of years to the start date.

What is an Anniversary?

An anniversary is a date that marks a significant event or milestone that occurred in a previous year, and is traditionally celebrated or acknowledged each year on the same date. The term is most commonly used to denote the years since the occurrence of a wedding or the beginning of a romantic relationship, but it can also be used to commemorate other significant events such as the founding of a company, the end of a war, or the death of a loved one.

Anniversaries are often celebrated with special activities, gifts, or rituals that reflect the importance of the event and the passage of time. For example, wedding anniversaries are often associated with specific gifts like paper for the first year, silver for the 25th year, and gold for the 50th year.

How to Calculate Anniversary?

The following steps outline how to calculate the Anniversary Ratio.

  1. First, determine the number of years since the anniversary event.
  2. Next, determine the total number of events held since the anniversary.
  3. Next, calculate the Anniversary Ratio by dividing the number of years since the anniversary by the total number of events held.
  4. Finally, check your answer by comparing it with the expected Anniversary Ratio.

Example Problem:

Use the following variables as an example problem to test your knowledge.

Number of years since the anniversary = 5

Total number of events held since the anniversary = 10