# Convert volume from voxels to mm^3 or cm^3
**URL:** https://discourse.itk.org/t/convert-volume-from-voxels-to-mm-3-or-cm-3/3280
**Category:** Beginner Questions
**Tags:** itkv5, image, itk-4122, simpleitk
**Created:** [July 13, 2020, 11:00am UTC](https://discourse.itk.org/t/convert-volume-from-voxels-to-mm-3-or-cm-3/3280 "2020-07-13T11:00:07Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@agatadefr](https://discourse.itk.org/u/agatadefr)
#### Post date: [July 13, 2020, 11:00am UTC](https://discourse.itk.org/t/convert-volume-from-voxels-to-mm-3-or-cm-3/3280/1 "2020-07-13T11:00:07Z")
Hey Guys,
I am quite new in ITK. I implemented using LabelGeometryImageFilter.
I extracted label volumes. Output results are in voxels.
I would like to convert to cc`3 or mm^3.
Could you help me how I can do that ?
What is the best way ?
I would be appreciate for any help.
Best 🙂
---
### Author:  [@dzenanz](https://discourse.itk.org/u/dzenanz)
#### Post date: [July 13, 2020, 1:38pm UTC](https://discourse.itk.org/t/convert-volume-from-voxels-to-mm-3-or-cm-3/3280/2 "2020-07-13T13:38:30Z")
Multiply the number of voxels by the volume of a single voxel:
```auto
auto sp = image->GetSpacing();
double voxelVolume = sp[0]*sp[1]*sp[2];
```
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### Author:  [@agatadefr](https://discourse.itk.org/u/agatadefr)
#### Post date: [July 13, 2020, 1:46pm UTC](https://discourse.itk.org/t/convert-volume-from-voxels-to-mm-3-or-cm-3/3280/3 "2020-07-13T13:46:48Z")
Thanks for reply.
I was thinking about something like this …
volume\_in\_voxels = labelGeometryImageFilter-\>GetVolume(labelValue);
volume\_in\_cc = volume\_in\_voxels/(spacing[0]\*spacing[1]\*spacing[3]\*1000)
But I am not sure that I am right … ??
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### Author:  [@dzenanz](https://discourse.itk.org/u/dzenanz)
#### Post date: [July 13, 2020, 1:47pm UTC](https://discourse.itk.org/t/convert-volume-from-voxels-to-mm-3-or-cm-3/3280/4 "2020-07-13T13:47:32Z")
That seems right.