Date Calculator Online – Free Date & Age Calculators

Use our fast, mobile-friendly date and time calculators to find date differences, calculate your age in years, months, and days, work out business days, track menstrual cycles, and even try the traditional Chinese gender predictor. All tools run instantly in your browser with secure processing.

Our Free Online Calculators

Age Calculator

Find your exact age in years, months, days, and total days lived, plus days until your next birthday.

Date Difference

Measure the span between two dates in years, months, days, and total days. Optionally exclude weekends for working days.

Working Days

Count business days between two dates while skipping weekends and custom holidays.

Period Calculator

Estimate upcoming periods, ovulation days, and fertile windows based on your average cycle.

Chinese Gender Predictor

Folklore-based tool predicting baby gender from mother’s age and month of conception.

Days Until

Count down the days, weeks, and months until any future date.

Next Birthday

See when your next birthday is, what weekday it falls on, and how old you will turn.

Add or Subtract Date

Add or subtract days, months, and years from a base date to find the resulting day.

Week Number

Find the ISO week number and year for any date.

Age Difference

Compare two birthdays to see who is older and by how much.

Time Duration

Calculate duration between two date-time points in days, hours, and minutes.

Day of Week

Find out what weekday a given date is, was, or will be.

Day Number of Year

See which day of the year a date is and how many days remain.

Age on a Specific Date

Check what your age will be on any chosen date in the future or past.

Birthday Calculator

Discover the weekday you were born, days since birth, and fun milestones like 10,000 days.

Anniversary Calculator

Track relationship or event length, and see when the next anniversary occurs.

How to choose the right date calculator

Whether you need to count days, plan a pregnancy window, or compare birthdays, pick the tool that matches your goal. Each calculator below opens instantly and shows your result with no sign-up.

Perfect guides to boost your planning

Want deeper explanations, examples, and keyword-rich walkthroughs? Visit our Date & Age Calculator Guides hub. You will find:

  • Step-by-step tutorials for date difference, age on date, working days, and pregnancy planning use cases.
  • Common search questions answered (e.g., “How many days until my due date?”, “How to add business days to a deadline?”).
  • Internal links to every calculator so search engines and readers can navigate easily.

Date calculators built for searchers

Browse every free date, time, and age calculator in one place. Each tool runs in your browser with instant answers and no login.

Looking for specific tasks like business days, milestones, or pregnancy planning? Use the links above to jump straight into the right calculator.

  • Fast, lightweight tools: no heavy scripts, no account walls, just results.
  • Mobile-friendly forms so you can calculate on the go.
  • Internal links between tools to help you discover the exact calculator you need.
Which calculator should I start with?

If you are unsure, begin with the Date Difference Calculator for general day counts, then check Working Days if you need to skip weekends.

Do I need an account to use these calculators?

No accounts or emails are required—every tool is free and loads instantly.