How to find the volume of an object

concrete footing.skp (113.9 KB)

I seem to recall there is a simple way to find the volume of an object. I thought it was to select the object and look under Entity Info, but that doesn’t seem to work in this case. Am I mis-remembering?

I’m attaching a file of this object–a precast concrete footing, which I need to calculate the weight of.

Thanks in advance.

Remove the internal faces and edges and group the object. Then the Entity Inspector will show it as a “solid group” and display the volume.


concrete footing revised.skp (22.5 KB)

OK, I removed the internal faces and edges (had no idea there was so much junk in there!) and made the object a group. File attached. Selected it, but Entity Info still states no volume. Is “Entity Inspector” something other than Entity Info?

Thanks Annssi

There is still an internal face between the footing and the pillar.


Anssi, you’re good!
I had deleted that face, not realizing when I replaced the face I’d deleted in order to see inside, I inadvertently recreated that internal face.
Now Entity Info says: 5.1605 cu. ft.

The reason you don’t see the volume measurement in the Entity window is because the “Entity” isn’t a volume, yet. You have to examine and fix it. When it shows a measurement, it’s also saying, “Congratulations, you’ve drawn a perfect shape”.
When drawing something like a hula hoop using the “Follow-me” tool, you can get various results depending on how well you use the tool. Should the Component be open or closed before clicking on “Follow Me” for example. When you open it, the selected line to follow becomes “un-selected” etc… Once you know the tool better you can use it in the right sequences and it will draw perfect shapes that show volumes. The volume measurement means you’re doing things the right way.

the ‘section cut tool’ is great for looking inside things…

delete it when your done fixing the geometry…


Thanks John–that’s a much better method…

Hi folks.

You can also hide a face or faces. Then, once the clean-up is done, Unhide them.

Another possibility (longer procedure) is to delete a face, do the the cleaning and then recreate the face by tracing a new edge. The trick is to avoid tracing an edge that may recreate an internal face. In your example, tracing a side edge would solve the problem. Or, tracing a diagonal also works if these is no matching diagonal on the opposite side. Once the face is created, delete the diagonal.

Just ideas.


Thanks Jean.
I like your hide-face option.
Something I like about this Forum and the Digest is the amount of my inadvertent learning.
For example, I watched the video about downloading from 3D Warehouse a model of the US Capitol building, then prepping it for 3D printing. I don’t actually foresee myself doing 3D printing in the near future. But in the process of prepping the model, Aaron used Edge > by color to discover off-axis lines that needed to be cleaned up. I’d never used that option. I once posted a model I was having problems with, and Forum members pointed out to me I had a lot of junk lines in my model. Had I been using Edge > by color, those junk lines never would have happened.

Hi All -

I have a similar issue - I am working on a landscape which currently falls away in one corner. We would like to build the site up to be level. Therefore I have created a landscape which reflects the existing and proposed levels and laid one on top of the other. I was hoping this would generate the volume so I’ll know how much top soil we’ll need. I have created the item as a group and hidden faces to search inside the item but the volume display remains unpopulated. Is anyone able to point me in the right direction on this please?

Hi Pen,

I’m guessing you don’t want to destroy the existing terrain geometry. Is that right?

SketchUp can only calculate the volume of a solid, in brief, a skin that completely encloses a region of space with no “leaks”. So you will need fo locate the flaws that are preventing your fill from being a SketchUp solid and correct them. I can imagine a lot of things, some as simple as drawing vertical edges to join the corners, but without seeing your model I can’t say why the region of interest isn’t solid. You could try ThomThom’s Solid Inspector 2 and see what it finds.

Hi Dave, the sole objective is to establish the volume - I’ll destroy what needs to be destroyed to achieve that if necessary.

Hi - ok thanks for tip - I’ll check out the Solid Inspector 2 - out of interest, how can a face be formed if there is a leak?

Of course, it depends on the exact nature of the leak. Sometimes it is simply that the corners of what might have been a face are not coplanar. You can fix that by drawing diagonals across the hole. Ultimately, any triangle is planar so you can “stitch” an opening closed by adding edges to create triangles. It you specific case, are the old and new surfaces in the same group? If they are in different groups they can’t possible close a solid.

I really can’t fathom why every person who has replied so far has decided to complicate the matter so much. Finding the volume of an object is way simpler than all of the suggestions supplied.
You simply select the whole object you want to find the volume for and if not already made into a group or component then do so. Once you have created a group simply right click and select entity info.
The volume is the 4th drop down info box in the default tray on your right as illustrated in the attached jpeg

even in this example which has a square mortice the volume is calculated, though I did find it questionable. I did this to calculate the volume of concrete I would need per post as a client of mine requires 5 2400mmx100mmx100mm posts erected for a lean to car port.
I know that for a 2400mmx100mmx100mm post I will need approximately 2 foot in the ground for maximum support and stability with a distance of 100mm all around on every side of each square post, therefore giving a depth of 600mmx300mmx300mm. Personally I was intriguied by sketchup’s answer for the volume and found it questionable? to sate my curiosity I deconstructed the form into 9 equal cubes/rectangles as I know the mortice is 100mmx100mm and the distance from the outside of the mortice to the edge of the block is 100mm each side(giving a total distance of 300mm for each side of the full block) this left me 8 cubes of equal size in the end because I obviously don’t count the mortice as this represents my 100mmx100mm post and I don’t need the volume for this(basic physics - no 2 entities of matter or no 2 masses can occupy the same space at any given time - duh!) in the end I calculated the volume of one of these cubes (0.01 m³) and multiplied it by 8 which gave me an end total of 0.08m³ I then multiplied this again by the number of holes I required for my posts. I know this is a very elaborate and elongated answer but hopefully it may help someone who is struggling with calculating volumes for materials. total concrete needed for my project in the end was - 0.4 m³ or
400 cm³ respectively due to there being 5 posts 0.08 m³ x 5.

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@michaellowegardening, thank you for your explanation.

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@g.h.hubers Youre very welcome glad I could help.

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BUT also remember that not everything you ‘group’ will show a volume in Entity Info - e.g. because it is not a ‘Solid’…
So then you’ll need to fix it’s ‘leaks’ etc than are preventing its ‘solid-ness’ - and therefore NOT showing a volume.
e.g. Delete one of the faces inside the example group and it is no longer shown as being a solid or having a volume !