Every date, counted exactly
Age, date, calendar and time calculators that give exact answers — down to the day, hour and second. No signup needed.
⭐ Featured tools
🆕 New tools
📚 Guides
🎂 Age
Age Calculator
Free age calculator. Enter your birth date to get your exact age in years, months, days and seconds, plus your next birthday, zodiac sign, and Hijri date.
Age Difference Calculator
Calculate the exact age difference between two people. Enter two birth dates and instantly see who's older and by exactly how many years, months, and days.
Date of Birth (DOB) Finder
Work backward from a known age to find a birth date. Enter years, months and days old to get the exact date of birth as of today or any date you choose.
Age on Any Date Calculator
Find out how old you'll be on a future date, or how old you were on a past date. One free calculator handles both directions instantly, no signup needed.
Birthday Countdown
See a live, real-time countdown to your next birthday — days, hours, minutes and seconds, updating every second. Free calculator, no login or signup required.
Half Birthday Calculator
Find your half birthday — six months after your birthday — and how many days until the next one.
Generation Calculator
Find your generation — Baby Boomer, Gen X, Millennial, Gen Z or Gen Alpha — from your birth year, with the year range for each.
Retirement Age Calculator (US Social Security)
Find your official US Social Security Full Retirement Age based on your birth year, using the real SSA schedule. Free, instant, no signup required at all.
Years of Service Calculator
Calculate exact years, months and days of service between a hire date and today, or any end date — useful for pensions, benefits, and HR recordkeeping.
↔️ Dates & Calendars
Days Between Dates Calculator
Calculate the exact number of days, weeks, months and years between any two dates. Free date difference calculator with instant, calendar-accurate results.
Date Calculator
Add or subtract days, weeks, months and years from any date to find the resulting date and day of the week.
Day of the Week Calculator
Find the day of the week for any date in the past or future — birthdays, historic events or upcoming plans.
Countdown Calculator
Count the days, weeks and hours until Christmas, New Year, Halloween, Thanksgiving or any date you choose.
Week Calculator
Add or subtract any number of weeks from a date, and find the ISO week number for any day. Free week calculator with instant, calendar-accurate results.
Month Calculator
Add or subtract months from any date, with end-of-month dates handled correctly — for example, Jan 31 plus one month correctly gives Feb 28, not an error.
Business Days Calculator
Count the number of business days (weekdays) between two dates, excluding Saturdays and Sundays. A free, instant business day counter with no signup needed.
Day of the Year Calculator
Find the day number of any date (1–366), how many days are left in the year, and how much of the year has passed.
Leap Year Checker
Check whether any year is a leap year, with the exact reason explained, plus the nearest previous and next leap years shown. Free, instant leap year checker.
Hijri Shamsi (Afghan Solar) Calendar Converter
Convert dates between the Gregorian calendar and Afghanistan's Hijri Shamsi (Solar) calendar in both directions — Hamal, Sawr, Jawza and all 12 Dari months.
Unix Timestamp Converter
Convert Unix timestamps (epoch time) to human-readable dates, and dates back into Unix timestamps. Free, instant conversion, works in your own browser directly.
⏱️ Time & Duration
Time Duration Calculator
Add or subtract time durations in hours, minutes, and seconds. Useful for scheduling, cooking, workouts, and stacking video or audio clip lengths together.
Work Hours Calculator
Calculate total hours worked from clock-in and clock-out times, with an unpaid break deduction. Free timesheet calculator for payroll and freelance billing.
World Time Converter
Convert any date and time between countries and time zones. Compare one exact moment across multiple cities at once, with automatic daylight saving handling.
👶 Baby & Life
Baby Age Calculator
Calculate your baby's exact age in weeks, months, and days, plus a general developmental stage label — newborn, infant, toddler, or preschooler. Free tool.
Adjusted (Corrected) Age Calculator
Calculate adjusted (corrected) age for premature babies — accounts for early birth when comparing developmental milestones, generally through about age 2.
Life Milestone Calculator
See the exact calendar dates for your 18th, 21st, 30th, 40th, 50th, and 60th birthdays and beyond, with a live countdown shown to each upcoming milestone.
♌ Signs & Fun Ages
Zodiac Sign Calculator
Find your Western zodiac (star) sign, its element and date range from your birthday.
Chinese Zodiac Calculator
Find your Chinese zodiac animal, element and yin or yang from your birth year, with a note for January and February birthdays.
Planetary Age Calculator
Find out how old you'd be on Mercury, Venus, Mars, Jupiter, and every other planet in the solar system, based on each planet's real orbital period today.
Tree Age Estimator
Estimate a tree's age from its trunk diameter using the standard arborist growth-factor method, without needing to count tree rings or cut it down at all.
Domain Age Checker
Check exactly when any domain name was first registered and when it expires, using live RDAP registry data. Free, instant domain age checker, no signup.
Frequently Asked Questions
Do I need to sign up or log in?
No. Every calculator works instantly without an account. A free account is only needed if you want to save results (up to 30) and see them later.
Is my data stored anywhere?
The numbers and dates you type are calculated in your browser and are not sent to us. We keep basic visit statistics (page visited, IP address, browser, time) and, if you save a result, that saved result in your account. The AI Assistant sends your question to an AI provider to answer it.
Are the results exact?
Date and age maths is exact. Money, tax and health tools are estimates based on published formulas and official tables, and are not professional advice.