Age Calculator

1. What Exactly is an Age Calculator?

If you've ever had questions like:

• "How old am I today, tomorrow, or 10 years into the future?"
• "How many days have I walked on this blue planet?"
• "How many days until my next birthday?"
• "How old is my favourite clothing brand?"
• "What's the age of my favourite celebrity?"
• "The number of years your company has been in operation?"

...then your simple answer is using an Age Calculator.

You could use your fingers to count or scribble on your mind board, but when you need precise and instant results, this Free Age Calculator is your go-to. It uses numerical data like a start date and end date to calculate the age accurately, every time.

No, it won't change its answer no matter how many times you ask. Don't believe us? Let's try it together!

2. How to Use the Age Calculator?

Our Age Calculator comes with three modes:

1. Calculate age by Birth Date
2. Calculate age by Birth Year
3. Calculate age by Birth Date and Time

2.1 Birth Date Mode

• Select your DOB or a specific date (month, day, year).
• Use the dropdown menu or date-picker for easy selection.
• Enter today's date or any custom date.
• Made a mistake? Easily change the data as many times as you like.
• Want to start from scratch? Press on Reset Fields.
• Once you're satisfied with your input, click on Calculate Age.

2.2 Birth Year Mode

• Enter your desired starting year and ending year.
• Click Calculate Age, and you're all done!

2.3 Birth Date and Time Mode

If you're obsessed with numbers and want to get to the bottom of every measurable second, this mode is your best friend.

• Enter start date and end date (month, day, year).
• Add the time (hours and minutes).
• Click Calculate Age to see results in time units such as hours, minutes, and seconds.

Let's understand these modes with a sample scenario:

Imagine, you have a younger sibling named Angel. Angel was born on January 26, 2000, at 9:40 AM. She claims she's 25 years old, but you're not inclined to trust her because she once ate your entire tub of ice-cream and left the empty box inside, misleading you. Thus, you wish to find out for yourself how old she really is by using our Age Calculator.

In the Birth Date Mode, enter January/26/2000 in the first row. Then enter today's date, say for example, July/18/2025 in the second row.

If you select Birth Date and Time Mode, additionally enter time of her birth in hours and minutes.

And if you select Birth Year Mode, just enter her birth year and current year.

Now, click on Calculate Age, and your answer will be generated.

Well, turns out she was telling the truth. She really is 25 years old. Regardless, if you want to be salty, then you can argue that she is 25 years, 5 months and 22 days old. You can know this by checking her age in different time units such as decimal years, months and days, weeks and days, and days, hours, minutes, and seconds.

You can even check how many days are left until her next birthday and prepare a gift in advance or return the favour with an empty box ;)

Similarly, you can calculate the exact age of someone or something as long as you have a start date and end date.

3. Why use Syntax Toolbox Age Calculator?

• Free forever: $0 platform fee. No additional software downloads required.
• Web-responsive: Hassle-free calculation on mobile, laptop, tablet, or computer.
• Default to user's today's date: Saves you a step.
• No date format confusion: Clean and simple input.
• Time zone smart: Automatically adapts to user's time zone.
• Leap-year friendly: Accounts for February 29 birthdays.
• Complete privacy: No backup stored on servers. Your sensitive data stays yours.
• Easy export: Copy or print results with a single click.

4. Running Age Vs Completed Age

4.1 Completed Age

The numbers of full years you've lived since your birth date.

For example, Angel was born on January 26, 2000. On January 26, 2025, she completes exactly 25 years. So, her completed age is 25.

4.2 Running Age

The year of life you're in. This is the age you're currently living.

For example, if today is Angel's birthday, then she turned 25, but she has already started living her 26th year. So, her running age is 26.

You can calculate the same with a simple formula: Running Age = Completed Age + 1

4.3 More Examples of Running Age vs Completed Age

Here's another way to put it more simply:

Completed age = Candles on your birthday cake this year.

Running age = Candles on your birthday cake next year.

5. How old am I in USA, or South Korea, or Middle East?

5.1 International Age (Western):

Most countries worldwide recognize the Gregorian calendar, which is based on the solar dating system. This calendar has 12 months and generally 365 days, with one leap year every four years (366 days). If your country follows this system, then your age is counted based on the number of birthdays you've celebrated so far. Your completed age is recorded on all legal or official documents, while the months and days in between are treated as just fractional parts of your age.

5.2 Islamic Age (Middle East):

Many countries in the Islamic World follows the Hijri calendar. It comprises of 12 months and follows the movements of the moon, making it a Lunar Calendar. The years are shorter in comparison to the Gregorian calendar as every month consists of only 29 or 30 days. If your country follows both the calendars, then your Islamic Age might be slightly ahead of your Western Age.

5.3 East Asian Age Reckoning:

Several East Asian countries traditionally follow the Chinese calendar, which is a lunisolar system similar to the Hebrew calendar. A regular calendar year has 12 months, while a leap year has 13 months. As per this counting system, you are considered one year old at birth. Your age increases collectively with everyone else on the Lunar New Year, not on your birthday. If your country follows this custom, then your child will be one year at birth and if the Lunar New Year falls just a week later, then your child would be considered two years old immediately after the New Year.

6. Will my age change if my time zone changes?

In short: NO.

Flying to a different time zone is not equivalent to time-travelling. You won't magically age an extra day or less. At most, it will push your birthday moment to a different local day.

And if you're still worried, relax.

Our Syntax Toolbox Age Calculator automatically detects your time zone and calculates age accurately, every time.

7. Why prefer Syntax Toolbox over other Age Calculators?

• Leap year, time zone shift, date format quirks confusion becomes a worry of the past.
• Get answer in seconds even down to the last second.
• Save brain space and computer space with fully online and zero sign-up process.

8. Real-life situations where our Age Calculator saves the day

• Travel Documents: Passport, visa, immigration forms often need exact age.
• Job Applications: Roles with minimum and maximum age requirements.
• Government Benefits: To check for retirement scheme, senior citizen perks, and social security.
• Insurance Policies: Age-based premium calculations for life, health, or travel.
• Sport Registration: Age brackets for tournaments, leagues, and competitions.
• Legal age checks: For drinking, driving, voting, or marriage eligibility.
• Event Planning: Celebration of milestone birthdays, anniversaries, or reunions.
• Pregnancy Tracking: To calculate gestational age or due dates estimates.
• Genealogy & Research: Calculate age from historical dates to map family trees.
• Custom Gifts: Engrave keepsakes with X days old or Z seconds together.

9. What if I'm bored of just calculating birthdays?

Here's cool things to calculate with our Age Calculator:

• Duration since any event in history: Figure out how long ago did the Titanic hit the iceberg.
• Time left until your next birthday: Send the party invites in advance.
• Age difference between twins: Count the exact seconds to settle who's older once and for all.
• Event Age Tracker: How old were you/will be at graduation, wedding, or any milestone-worthy moment.
• Relationship Age Gap: Because about three years isn't satisfying enough.
• Trip Tracker: Review the days since your last vacation so you know when you're overdue for another.
• Future Age Check: How old will you be by 2050?

10. Other Methods to Calculate Age

10.1 Fun Math tricks to Guess Someone's Age Without a Calculator

If you enjoy playing with numbers or just want to get the gears of your head rolling, then we have the perfect exercise for you. Use these tricks to impress your friends and family, or simply to improve your mental math speed.

10.1.1 Find your friend's age using a random number

• Tell your friend to choose a number between 2 and 10.
• Once they select a number, ask them what it is. Suppose they select the number 4.
• Multiply that number by 2. For example, 4 x 2 = 8.
• Add 5 to the answer. For example, 8 + 5 = 13.
• Multiply that further by 50. For example, 13 x 50 = 650.

• Now, there will be two scenarios.

  Case 1: If your friend's birthday has already passed in the current year, add 1767.

  Case 2: If your friend's birthday is still yet to arrive, add 1766.

• Please note that this trick was compatible with the year 2017, so to make up for that gap, add a number for every plus year in the original 1767 or 1766. For example, if we assume the year is 2025, then it will be 1767 + 8 = 1775 or 1774 respectively.
• With these additions, your final calculation will be 650 + 1775 = 2,425 or 2,424.
• Lastly, subtract this answer with the year your friend was born in. For example, 2,425 - 1997 = 428.

There you have it!

Upon close analysis, you will find the digit in the hundredth place (4) is the number your friend originally chose in the beginning. The last two digits (28) reveal his current age.

Fun, right? Let's try another trick!

10.1.2 Find how old you'll be in future.

• Multiply your current age by 2. For example, 28 x 2 = 56
• Add your birth year. For example, 56 + 1997 = 2,053
• Please note that this trick has limitations and the answer will always be the year when you turn double your current age.

You will be 56 years old in the year 2053.

10.1.3 Check your age on December 31 of any year - past or future.

• Suppose you want to calculate age for December 31, 2035.
• Subtract your birth year from that year. For example, 2035 - 1997 = 38.

Your age on December 31 of 2035 will be 38 years.

10.2 Built-in formulas to calculate age using Excel.

For those who live between the rows and columns of spreadsheets.

1. To calculate age in years, use this formula → =DATEDIF(Birthdate, Today, "Y")

For example,

2. To calculate age in years, months, and days, try this → =DATEDIF(Birthdate, Today, "Y") & "y " & DATEDIF(Birthdate, Today, "YM") & "m " & DATEDIF(Birthdate, Today, "MD") & "d "

For example,

3. To calculate age in decimal year, consider this → =YEARFRAC(Birthdate, Today)

For example,

10.3 Calculate age using JavaScript

JavaScript

Copy Download

function calculateAge(birthDate) {
    const today = new Date();
    
    if (isNaN(birthDate.getTime())) {
        return "Invalid birthdate provided";
    }
    
    if (birthDate > today) {
        return "Birthdate cannot be in the future";
    }
    
    // Calculate age in years, months, and days
    let years = today.getFullYear() - birthDate.getFullYear();
    let months = today.getMonth() - birthDate.getMonth();
    let days = today.getDate() - birthDate.getDate();

    if (days < 0) {
        months -= 1;
        const prevMonth = new Date(today.getFullYear(), today.getMonth(), 0);
        days += prevMonth.getDate();
    }

    if (months < 0) {
        years -= 1;
        months += 12;
    }
    
    const yearText = years === 1 ? 'year' : 'years';
    const monthText = months === 1 ? 'month' : 'months';
    const dayText = days === 1 ? 'day' : 'days';
    
    return `You are ${years} ${yearText} ${months} ${monthText} and ${days} ${dayText} old.`;
}

// Change this to your birthdate
const birthDate = new Date('1997-07-18');

// Calculate and display age
const result = calculateAge(birthDate);
console.log(result);

11. Reasons to choose Syntax Toolbox over these alternatives

While excel formulas and coding scripts can be powerful, they're not always convenient. Syntax Toolbox Age Calculator gives you:

• Instant results: No extra need for formulas, codes, or apps.
• User-friendly: Calculate on the go. Zero setup required.
• Precise breakdown: Not just years, months, and days, but to the very last minutes and seconds.
• Error-proof: Break-free from the trap of formula typos, wrong codes, and miscalculations.
• Universal format: Removes DD/MM/YYY OR MM/DD/YYY mix-ups.
• Shareable results: One click is all it takes to export or copy.
• All-in-one tool: Forget about switching tabs or apps.