Age & birthdays
Calculate an age on a specific date, check total days, and find the next birthday using an explicit leap-day convention.
Calculate an age →EVERYDAY CALCULATORSClear figures.
Clear figures.
Useful answers.
Practical calculators with visible assumptions, private browser processing and results you can keep.
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Find the figures you need.
Percentages, prices, ages and planning dates, with the working steps included.
Intervals & date offsets
Compare dates, include both endpoints when appropriate, or move forward and backward by years, months, weeks and days.
Compare two dates →Working-day planning
Count or add working days using a custom weekend and holiday list. Review exactly which days were excluded.
Plan working days →Check a percentage, price or split
Use the Percentage & Discount Calculator for common percentage questions, reverse calculations, stacked offers and bill splitting. Review inputs, formulas and rounding before keeping a report.
Choose the counting rule that matches your task
Calendar days and working days answer different questions. An elapsed date difference excludes an extra inclusive day, while a schedule may need to count both endpoints. Month and year offsets also require a rule when the target month has fewer days.
Keep the result and its assumptions together
Download TXT, CSV or JSON reports with your entered dates and options. For a single result date, export an all-day calendar event. The calculator does not connect to your calendar account or upload your input.
Related work
Use the Invoice & Quotation Generator to prepare business documents, the PDF Form Filler to enter dates into forms, and the Word Counter & Text Cleaner to prepare accompanying text.