Trying to solve problem for which I asked help in Looks like total number of parts and sum of them differs on bricklink I understood I did not have the skills to check contents of a set. I did Web search for "site:bricks.stackexchange.com how to check completeness of a bought set" and did not find relevant info so making new post. The question How to check the missing pieces of a given set? is titled similarly, but asks about different thing from mine.

Initially I tried to count parts by tens, put them in one place and keep count of tens. I miscounted set of 602 by about 10‰ of parts. Then I tried to go by bricklink list again keeping track in tens. Again I failed though twice less.

Finally I separated parts by each "type", taking large area on the floor and going by bricklink list I glanced at the parts, checked presence and added up. On that way I found several occasions where I misplaced parts, but finally I got exact count, so I bought complete set as expected. Picture of layout below:parts of a set

What are your favorite ways to check completeness of bought sets?

4 Answers 4


You've already discovered yourself two good ways:

  • count by ten
  • put elements on large surface by type

The latter technique can be extended to an art called "knolling": knolling

Place all elements by type in right lines with right angles on a large surface... Its a very relaxing exercise and fun in its own right. Checking completeness becomes trivial, building afterwards can also be done with much less frustration.

Update: Here's another very impressive knolling. The UCS Millenium Falcon 75192 (7541 pieces) https://i.redd.it/q51wrtua5yb41.jpg (can't insert picture here directly since too large)

  • 4
    offtopic: WOW @ the amount of colors in a black-and-white set...
    – Raidri
    Commented Jan 6, 2020 at 13:58
  • 3
    @RaidrisupportsMonica, off topic but interesting in it's own right. All colored bricks will be inside the model and not visible from the outside. That is very deliberately done to make the building process easier. I would consider building an entire black and white model from instructions a PITA Commented Jan 6, 2020 at 14:08
  • 1
    The amount of content this picture brings me is almost disturbing.
    – Tim S.
    Commented Jan 7, 2020 at 16:13

This might sound crazy, but:


Follow the instructions step by step and you will see when something is missing. You can make a copy of the instructions and strike out every part you have used if you have trouble keeping track.

  • 5
    Welcome to Bricks.SE. It isn't crazy, but it is very frustrating to be halfway through building something substantial to realize that there's no way to finish it. Missing pieces from LEGO are rare so folks get used to everything just being there. In the aftermarket missing pieces are normal so it is a good plan to verify.
    – chicks
    Commented Jan 6, 2020 at 13:44

I have found that following solution works best for me.

  1. Download and install BrickStock. This software has multiple uses, however for this case we would explore just a single feature.
    1. Once installed go to File > Import > BrickLink Set Inventory and filter by set number. Don't forget to select All Items in Category list.
    2. Now you need to select all parts (Ctrl+A) and set quantity of all parts to zero (right-click any item while all of them still selected and Quantity > Set > 0)
    3. Now you have a full list of parts within that particular set. Here is your main job to seek parts you have and mark their quantity accordingly within the list.
    4. In the end you'll have a list of parts you actually have. For next step I suggest you to delete lines for Counter Parts (noted as CP in first column) and, if you don't need to check against extra parts, remove lines with + in first column too.
    5. Save your file and note its location.
    6. Go to Rebrickable and login with your account.
    7. Create custom list via My LEGO > My Custom Lists menu > "Add new list" button
    8. Import your previously saved list you created with BrickStock software using "Import/Delete Parts" button into newly created custom list.
    9. Once completed, go to Sets > Compare Sets menu within Rebrickable and choose you custom list on one side and a set you are checking against on the other.
    10. You will be presented with a of bit of details, with shared parts as well as unique ones. Unique parts listed under set's inventory are the ones you are missing.

I've used this quite a few times to check used sets I bought.

Alternatively, you can just create a list of parts you have following steps 1-6 above and compare it manually with set's inventory on Bricklink. This worked for me as well.


You're definitely going in the right direction with this. I've done this for sets that family had that had missing pieces as well as to part together sets that I wanted to build.

  • I print out the bricklink part list, sorted by color. I write on the part list how many I find of each part.
  • To help with sorting the parts I will stack things that are easy to put together and get apart like bricks. Tiles can be stacked as well, but it is probably better to zig-zag a one stud gap between each layer of tiles so you have a chance to get them apart later. I find that the stacking of the parts makes it much easier to manage the bricks during the process as well as count them.
  • For times when you have hundreds of a given small part I'd weigh them and divide by the bricklink weight per part to get a reasonable estimate of how many you have.
  • I find bamboo cutlery trays are excellent for sorting. The trays that came with the Architecture Studio are excellent as well.

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