Does the Grimm's Large Stepped Pyramid work with Unit Blocks?

This question comes up a lot - does the Grimm's Large Stepped Pyramid work well with Unit blocks?

The short answer is no. These two block set have totally different mathematical standards and they're not aligned. Grimm's blocks are based on a 4cm (40mm) cube unit, while standard unit blocks are based on a 5.5 x 2.75 x 1.375 inch unit block (if you want that in mm for comparison's sake it's almost exactly 140 x 70 x 35mm). 35mm and 40mm just aren't the same. They're not friends and they really super duper don't work together mathematically.

Here's a comparison of the two "units".

and here's a comparison of some other pieces in these sets-

Because these blocks aren't aligned mathematically it's not easy to build with them all together. We have both in our home but my kids prefer unit blocks - a few months ago my 5 year old even asked me to remove the Grimm's sets from our playroom in favor of having more space for unit blocks. When these sets were still all together the way my children used them all was still pretty separate. My kids have a deep understanding of block play and they know that the tw0 systems don't align so when using these sets alongside each other they would usually end up building lots of structures nearby each other with the separate types of blocks. Or they would build in layers - with the different types of blocks building upon each other without really interacting. In this way my kids often ended up using the Grimm's blocks more like loose parts for decoration instead of as a building tool.

The worlds they build with all of these blocks together are beautiful, but if you're trying to build a unified collection I don't recommend mixing these sets. Instead I recommend choosing one system and sticking with it. There are so many options for both 4cm block sets and unit block aligned sets so truthfully there's no reason to mix it all up. Grown ups who choose to do this usually do it because the sets are pretty and they want them all, not because their kids are wanting or needing both.

When it comes to block play, it’s worth choosing a system and sticking to it. By providing kids with open-ended toy systems that actually work together, we support their mathematical and scientific learning and—just as importantly—we facilitate meaningful independent play by removing points of frustration (like blocks that don’t align). Will kids figure out how to play with these sets together? Almost definitely yes… but should they have to?

It's important to think about why you're introducing what you bring into your playroom before you make that purchase. What do you think?

If you'd like to learn more about purchasing unit blocks you can check out my unit block buying guide here.

Here's a list of block accessory sets that are aligned with Unit Blocks.

And here's a list of some block sets that are aligned with the Large Stepped Pyramid.

P.S.- Links in this post may be affiliate links which means I may receive a small commission at no additional cost to you if you choose to use them - thanks for your support!