Your birthday is the perfect day to celebrate who you are and what you love. It's an opportunity to rejoice in another year of life while you party with friends and family. Of course, birthdays are also a time to celebrate your accomplishments and the challenges you've overcome. If birthdays weren't such a big deal, would the Beatles have sung about them?

All birthdays are special and worthy of celebration. But some birthdays are a sign that you’ve reached a special age — like the Sweet 16, Big 21, and 50-year mark — are true milestones.

You want to go the extra mile to celebrate these birthdays, and that all starts with creating an invitation that stands out from the crowd. Check out these birthday party invitation ideas that are perfect whether you're celebrating a Sweet 16 or Fabulous 100.

Sweet 16

In many cultures, turning 16 is a big deal. Celebrate the big day with a modern invitation that captures your spirit. Remember to keep your invitation simple and include all the details your guests need to know. It's okay to keep some details under wraps but ensure your guests know where the party is and when it starts and ends.

Consider including a dress code if you're throwing your first big, fancy party or want your guests to show up in themed wear. Pool party, anyone?! Of course, you can use these birthday party invitation ideas if you're celebrating a 15th birthday quinceañera. Don’t forget to include an RSVP section so that you have a headcount for your party.

Grown-up at 18

It's official: You can vote. Your 18th birthday marks the day you become an adult in many cultures. Going with the theme of being all grown up, Mixbook offers these Black & Gold invitations with bright, shiny stars to welcome in the bright new you. Whether you're off at school or sitting poolside with Mom and Dad, plan something fun for yourself – you deserve it.

This is a great time to plan your birthday party, too. Of course, it's fine to stray from the Black & Gold theme. Mixbook has dozens of birthday party invitation templates. If you have a flair for graphic design, you can start with a blank canvas and make the invitation of your dreams.

Finally 21

Uh-oh. The big 2-1. The game changer. Doors everywhere are now officially open, and the world is your oyster. This is a milestone to remember!

Celebrate your newfound freedom by throwing a big party that highlights your 100% adult status. It's fine to include adult drinks if that's your style, but don't feel pressured to throw a boozy 21st birthday bash. It's fine to celebrate however you'd like. After all, it's your birthday!

Thanks to Mixbook's colorful assortment of invitations, whether you're ringing in your year with a sophisticated Tassel Garland style get-together or partying with magical style, you can ensure your day is one that reflects YOU! If you’re not sure where to start, check out this blog with info on using our birthday invitation templates.

Dirty 30

You're turning 30. How did that happen? Are you old now? No way...you're just getting started!

We know that 30 is when the realization that you're living the adult life starts kicking in. It's also a great time to throw a party with the help of a few birthday party invitation ideas.

There are no hard-and-fast rules about how you should celebrate your 30th birthday. Think about what you love doing – maybe you want to have a movie marathon with a close-knit group of friends or invite the whole neighborhood over for a big cookout. Remember to include RSVP instructions so you know how many guests to plan for.

What matters is that you celebrate what makes you unique and what's brought you this far in life. So whether you're going out wine tasting with friends or having people over for a wild milestone birthday game night, be sure to do it up right. After all, you'll never be 30 again!

The big 4-0

You're turning 40! But don't sweat it – your 40th birthday is the new 29. It's like riding a bike and ripping off a Band-Aid all at once (or something like that) – you can do it! And when you do it, you're going to show them how it's done! Choosing invitations that fit your party theme is a great way to let guests know what to expect.

For a night out on the town, Mixbook offers birthday big leaguers some pizzazz with a little sparkle and a lot of elegance in the timeless Milestone Celebration invitation. If you're planning something a little more subdued, try the Chalkboard Celebration card that marries casual design with great style for the perfect backyard dinner with friends.

Nifty at 50

You know what they say: 50 and fabulous! We know that your golden years are still to come and that turning 50 is a drop in the well of your fabulousness. So, plan something with the girls and invite them using this striking Floral Wreath Birthday invitation that suits day or night.

If you're looking for something more glamorous, check out the Geometric Collage. Of course, your 50th birthday is a great time to opt for one of our gold-foil invitations. No matter your chosen theme, you’ll find Mixbook invitation designs to match it. After all, there's no excuse not to celebrate this major milestone!

Sweet at 60

You were sweet at 16, and you're even sweeter at 60! Your 60s are a great time to celebrate the wonder of your golden years while surrounded by family and friends. If you're opting for a simple 60th birthday celebration, consider the Classic Birthday Invitation. Beautiful and understated, it's just like you!

Perhaps you want to celebrate your 60th with a little more splash and pizzazz. Why not choose these stunning Painted Rainbow invitations? No matter your style or how you plan to celebrate turning 60, it should be all about YOU.

After all, you've worked hard to make your golden years fabulous. Your life and accomplishments are absolutely worth celebrating. Don't forget to create a milestone photo book to celebrate the occasion, too!

Thriving at 70

Turning 70 is a major milestone. You might have grandchildren or even great-grandkids with whom you want to celebrate. Or, maybe you're looking forward to a sophisticated tea party or night out with your closest friends. No matter what you choose, make sure that the event reflects what you really love.

We love these pretty Watercolor Party invitations to announce a low-key night out on the town with your friends. But maybe you want to add a touch of fun and flare instead. Opt for these shimmering Sparkler Birthday Invitations that will delight guests of all ages.

Fantastic at 80

You made it to 80! Your birthday is a major milestone; you deserve to celebrate however you'd like. Use this Simple Gold invitation to let your friends and family know when and where they can celebrate with you.

Maybe you're not turning 80, but you're planning a surprise party for someone who is. Our It's a Surprise Party invitations let guests know you're hosting a birthday party but don't want to spill the beans.

Amazing at 90

Your 90th birthday is the perfect time to throw a big party that showcases the amazing life you've had so far. Remember that this birthday is all about YOU. Want to celebrate with a few close friends? That's great! Want to throw a big bash? That's fine, too!

Invite everyone to the bash with this Modern Collage card. You can use photos of yourself from the past decades to show off how gracefully you've aged. Or embrace the flair of the Roaring Twenties with this Gatsby Celebration invitation.

The astounding 100

More and more people are living to see their 100th birthday. If you're a soon-to-be centenarian, you have cause to celebrate! At 100, you know exactly who you are, and you deserve to celebrate however you'd like. Mixbook offers dozens of custom birthday invitations suited to every theme and mood, from pretty pastels to neon confetti. Pick the one that speaks to you – you deserve it!

Are you ready to make these birthday party invitation ideas your own? No matter what milestone birthday is approaching, you'll find designs that suit your style at Mixbook. Of course, you can customize all our templates with your own color scheme, fonts, and stickers. Get started on your custom cards today.