I have a relatively large LEGO collection and I would like to know roughly how many pieces I have; however, it would not be worth my time to count each piece individually. Is there a faster way to estimate the number of pieces? Is there is a way to tell by their weight?

  • what's the "known number of parts/ unknown number of parts" ratio of your collection? do you mainly own lego SETS, do you frequently mailorder individual PARTS, do you even buy BULK by weight?
    – Uli
    Apr 10, 2019 at 9:28
  • I own a good deal of sets (maybe 5% of my total collection), but the majority of my collection is pieces. I'd say I buy from Bricklink monthly, and I have not yet bought bulk by weight.
    – Magnus
    Apr 10, 2019 at 16:51
  • i'm not too familiar with bricklink, but i think you can download a list of purchased items. since you bought the majority of your collection there, the data in that list should tell you what some roughly 95% of your inventory are in numbers...
    – Uli
    Apr 10, 2019 at 19:13
  • Hmm... Well, even if that were possible on Bricklink (which it might be, I haven't checked), that would still only cover about another 20% of my collection, as a lot of my parts are from disassembled sets.
    – Magnus
    Apr 10, 2019 at 20:47
  • If you have just sets (without additional loose bricks) it might be easier to add all of theese sets to your collection on Rebrickable. It will then give you more details, like number of parts, estimate value, etc.
    – Alex
    Apr 11, 2019 at 20:15

2 Answers 2


What a tricky (bricky!) question. Let's estimate...

By Weight

So, can one estimate the number of bricks in a bag or box by weight?

In fact, they do weigh bags and boxes over at the factory to make sure there aren't any parts missing. But of course they're just comparing expected weights.

  • That's why you can't simply weigh a big mix of unknown bricks to calculate their number. There's no reference.

However, you can use a scale to estimate a number of bricks, if you have sorted them out individually.

If you keep your pieces in trays or drawers and you have a big bin of identical pieces (2x4's, 2x1's, ...), you can estimate them by weighing them.

  • Weigh them all, then divide by the weight of a single one.

Gets close. Speeds things up.

By Numbers

Anyway, try to narrow things down. To do so, collect as much data as possible.

  • Which sets do you own? Look up the number of pieces per set.
  • Take into account if you bought an incomplete set. How much is missing?
  • Did you mailorder pieces?
  • Can you estimate the amount? Maybe check your orders/ accounts.
  • Did you buy a considerable number of bulk?

All this should already give you a rough number, considering the sets/mailorder/bulk ratio.

By Eye

  • Do you sort out your Lego into trays and drawers? You could count some of them, calculate an average amount and project it.
  • What about the relevance of certain parts? Do they count? Where there's lego technic, there's plenty of technic pins. You could simply leave out those piles of pins and separators or weigh them. If they're sorted out, of course.

(Disclaimer: Do not take this last part too seriously...)

Or is it all in ONE BIG BIN?

Well, let's see.

  • How can one estimate the number of people in a crowd?

Take an aerial view, divide it into sections, count people in one frame and multiply by frames. As long as people are spread out evenly, you should get close enough.

enter image description here

Example: There are (maybe) 63 minifigs in this picture. Count all minifigs in one of the frames and multiply them by four for a rough answer.

  • How can one estimate the number of jellybeans in a jar?

enter image description here

Find out about jar and jellybeans, diameter, height, volume. Calculate. As long as you're not getting peckish, you should win big.

Now, how can one estimate the number of bricks of completely different shapes and sizes in ONE BIG BIN?

  • In theory, you would stirr everything to get one humongeous mass.
  • That is, you want bricks, pins, wheels, minifigs, separators all next to each other, not in different layers with small parts at the bottom of the bin. Next, pour it out and spread it evenly. Take a photo. Use the method mentioned above.
  • Or, leave it in the bin. Take out one cup full of Lego, count the parts, determine how many cups your bin holds and extrapolate.

Conclusion: You're better off counting. While sorting out.

  • Thank you, this is extremely helpful. I might try a few different methods and average their answers. That'll probably get me as close as possible. :)
    – Magnus
    Apr 10, 2019 at 23:24
  • I can only add that "by eye" method is a bit tricky. I've seen bunches of bricks and allways underestimated the numbers. It is like you cannot believe there are 100 bricks of the same type. More like 50-60. But then you go count it and here you go - 100 bricks.
    – Alex
    Apr 11, 2019 at 7:16
  • Right, that's an excellent point. Maybe I'll estimate a smaller number "by eye" and then I'll count to see how accurate I am or am not. :)
    – Magnus
    Apr 11, 2019 at 21:25

If the parts came from sets then you can search bricklink.com for the sets, and it will then tell you how many parts is in each set. It is then just a matter of summing them up.

If the parts are not part of a set then im afraid there is no easy way to do that, especically if the parts are quite varied.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.