What’s the most challenging part of a Christmas countdown calendar for you? I want to make one every year, and I don’t. I have since discovered that a successful countdown calendar or advent calendar has much to do with making the Countdown activities simple and fun. Read on to find out some of our favorite Christmas STEM activities for kids for an easy, simple, and fun Christmas countdown. 


Get ready for our 25 days of Christmas STEM Countdown Calendar. Check out 25 easy to do Christmas STEM activities to try at home or school. Family friendly and super fun experiements for kids!! #STEM #Christmas #science #experiments


This holiday season, join us for awesome science and STEM projects filled with festive fun! I have compiled a list of 25 Christmas STEM activities for one great Christmas countdown calendar, including science, technology, engineering, and math.

These Christmas countdown activities perfectly combine easy science experiments for kids and Christmas fun!

How you present each activity is up to you. I have a little tree I like to use for our countdown calendar. On the tree are mini clothespins holding a little-numbered card with the activity written on the back.

Another simple idea would be to make a paper chain with an activity written on each link. You can find more DIY Advent Calendar Ideas here.


I am going to start before December 1st so that I’m prepared and ready to go on the 1st! If you are late to start, jump in anytime! If you can’t do all 25 days of Christmas activities, pick a few and add other special ideas to round out the days.

I have chosen to do these Christmas countdown activities for a few reasons.

  • One, I know my son will enjoy them.
  • Two, they don’t require a ton of time. It’s a busy season!
  • Three, the supplies are simple and can be found easily.
  • Four, I think these ideas are all quite frugal.

Many of the items can be reused—some items you may already have on hand. You could even hint at the day’s experiment with one of the supplies.


Easy to make Christmas Science Countdown Calendar tree artificial tree and paper


Below, you will find the link to each Christmas activity. Click on the title, and you will be taken to a new page to see step-by-step instructions. If a title doesn’t open to a new page, we haven’t done the activity yet, or it’s pretty self-explanatory!

Click here for your Christmas FREE STEM cards

DAY 1: Science with Cookie Cutters

DAY 2: Make Christmas Slime!

Includes Tinsel Slime, Rudolph’s Nose Slime, Gingerbread Man Slime, Candy Cane Slime, Christmas tree slime and more! We have several basic homemade slime recipes that can be dressed up with many themes.

BEST Holiday slimes recipes and STEM activities for Christmas slime making. Make slime for Hanukkah, winter snow activities, and New Years! These are some of the best Christmas slime activities and experiments for kids! #STEM #slime #Christmas

DAY 3: Gumdrop Engineering

DAY 4: Grow Crystal Ornaments

ALSO CHECK OUT: 50 Christmas Ornament Crafts For Kids

crystal snowflake ornaments

DAY 5: Tinker Time

  • Christmas Tinker Kit: Fill a box with themed items like tape, pipe cleaners, styrofoam, paper clips, bells, and other fun finds. A dollar store is a great place. This activity will be used multiple times, guaranteed! Keep glue and scissors available too.
  • Christmas STEM Challenges: Pair it with one of these printable Christmas STEM activities.

DAY 6: Time to Launch Things

  • Christmas Catapult: Popsicle sticks, rubber bands, marshmallows, jingle bells, pom poms, little paper presents.
Christmas STEM Activity Simple Catapult

DAY 7: Explore Static Electricity 

DAY 8: Make a Geoboard

DAY 9: Santa’s Magic Milk 

Santa's Magic Milk Experiment

DAY 10: Candy Cane Science

  • Dissolving Candy Cane Experiment: Small candy canes, clear cups that will fit candy canes, a variety of liquids such as water, cooking oil, vinegar, seltzer, milk. Large candy cane and a shallow bowl for disappearing stripes.

DAY 11: Erupting Ornaments

DAY 12: STEM Challenge!

DAY 13: Exploring Magnetism

Magnetic Ornaments on tree Christmas craft activity

DAY 14: Screen-Free Coding

DAY 15: Santa’s Five Senses lab

DAY 16: Non-Newtonian Fluids

DAY 17: Design a LEGO Marble Maze

LEGO Christmas Marble Maze STEAM Christmas Countdown

DAY 18: STEM with Shapes

DAY 19: Santa’s Balloon Rocket

DAY 20: Tallest Tree Challenge

Christmas Tree Cup Tower Challenge: Large green plastic cups.

This Christmas cup tower STEM is a great science experiment for kids! One of the simplest experiments for kids to try this holiday season!

DAY 21: Candy Science

DAY 22: Santa’s Zip Line

  • Santa’s Zip Line: Small plastic Santa, small laundry line pulley {harder store $2}, rope, tinker kit of materials to build a holder for Santa. Check out this very fun indoor zip line we had a blast setting up.

DAY 23: Gingerbread Structures

  • Gingerbread Structures: Use gingerbread cookies, graham crackers, or gingerbread man cookies, and frosting to build structures. Tasty engineering and a holiday snack.

DAY 24: Track Santa’s Flight

  • Tracking Santa: Map, compass, computer or smart device. Check it out for all the details.

DAY 25: Cookie Science

  • Cookie Science! Chocolate Chip Cookie Recipe Variations

We always bake cookies on Christmas Eve, so we will save this one for the 24th! I love Serious Eats: The Food Lab’s Best Chocolate Chip Recipe.


Looking for even more ideas to add to a Christmas countdown! Check out the cards below!


I hope you enjoy your holiday season filled with discoveries, explorations, and new Christmas activities with our Christmas STEM countdown calendar. Sharing these activities at home is a wonderful family experience.

Click on the images below for more ways to enjoy Christmas STEM and science below!


  1. You will see that some days are already linked up just click on the title. I will be adding as we go along for the rest! Thanks!

  2. This is such a fun and unique way for kids to learn while counting down to Christmas. A couple of years ago we started doing STEM activities and science experiments while we were decorating, finding old candy in the Christmas decorations boxes, and the like.

  3. I LOVE this idea – I pinned it too. So many of these activities are kitchen science – which gets kids comfortable for future cooking projects too! Yay!!

  4. Yay, well done you for getting a countdown together. Love the ideas and this would be a great way to introduce stem activities to my kids.

  5. Kids love science and they love Christmas, so parents can’t go wrong with any of the science experiments on your list 🙂 I have pinned it for December.

  6. What a fabulous idea! I love integrating science into real life events like the holidays — can’t wait to try some of these with the kids this year.

  7. Is there a recommended age minimum? Just wondering how well it would work to try these with my 3 year old.

  8. Hi! We started science with our 3 year old. You can take parts of different activities to suit your needs. I think many can be done with a three year old with plenty of supervision. We also have a 25 day sensory play list too that might have some ideas to mix in. I know the mini christmas eruptions would be lots of fun as well as making magnet ornaments but the binary code ornaments might not be much fun other than just enjoying putting beads on the pipe cleaner. Definitely building a cup tower tree would be fun! If your child isn’t going to eat things, are homemade slimes are fun {but not edible!}. Feel free to email me with any questions and if you haven’t already subscribed to our mailing list, please do so as we will have more fun ideas coming out soon for Christmas!

  9. I love, love, love these ideas. Thank you for sharing. I was very interested in the Christmas tangrams, but there isn’t a link to the printout. Could you please share that. Thank you so much!

  10. LOVE this! Did I miss a link to print the advent calendar? I can only find the links to the different activities but not the cards… thank you!

  11. Thank you so much for this amazing list of ideas. We have done a handful so far (out of order) and my 6 and 4 year old are loving it!

  12. I have tried to download the Christmas STEM cards twice now and I haven’t gotten them. Are they still available?

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