Age calculator
MathCalculate the exact age in years, months and days between two dates.
Your results
Calculate exact years, months and days between two dates.
How exact age is calculated
We compute the difference between the two dates adjusting for month lengths and leap years, producing a precise result in years, months and days.
Includes the end day
By convention age is calculated up to the target date without including the next day. If you need a different rule, just change the target date.
Frequently asked questions
Answers to the most common questions about this tool.
How is this result calculated?
It applies the mathematical rule shown by this calculator to your inputs.
Can the result be greater than 100%?
Yes, when the relationship between the entered values is larger than the reference value.
What is this calculation useful for?
Use it for quick checks, study, and everyday calculations.
Which values can I enter?
Enter valid numbers in the fields and check any required format.
What happens with zero or invalid values?
The tool prevents or flags operations that are not mathematically defined.
Sources and methodology
Methodology: Age between dates
Compares JavaScript dates and decomposes the difference into years, months, days, and total days.
Handling of earlier target dates is a ToolsRL implementation decision.
References
No external reference is required: the mathematical calculation is described above.
Last reviewed
July 15, 2026