Why Scaling Matters
Every STL file has a default size — but that size might not be right for your space, your printer, or your use case. The good news: scaling is one of the easiest things to do in any slicer.
In PrusaSlicer
1. Import your STL file (File → Import → Import STL)
2. Click the model to select it
3. On the right panel, click the **Scale** icon (looks like arrows pointing outward)
4. Check the **lock** icon to scale uniformly in all dimensions
5. Type in your desired percentage or target dimension
6. Click anywhere else to confirm
Pro tip: You can also right-click the model and choose "Scale to fit" to make it fill your print bed, then reduce from there.
In Bambu Studio
1. Import your file
2. Select the model on the build plate
3. In the object properties panel on the right, find **Scale**
4. Click the chain-link icon to lock proportions
5. Type a percentage or a specific dimension in mm
Bambu shortcut: Press S while a model is selected to open the scale dialog directly.
In Cura (Ultimaker Cura)
1. Import your STL
2. Click the model to select
3. In the bottom-left toolbar, click the **Scale** icon (the arrows)
4. Enable **Uniform Scaling** (the lock icon)
5. Type a percentage in any field
How to Figure Out the Right Scale
Method 1 — Measure your space:
Measure the space in mm where you want to put the object. Divide by the object's current dimension (shown in the slicer). Multiply by 100 = your scale percentage.
Example: You want an organizer 80mm wide, but it's currently 100mm → scale to 80%
Method 2 — Just eyeball it:
Print a small test at 50% first. See if the proportions look right and scale accordingly.
Important: Scaling Affects Tolerances
If a part has a snap fit (like a pill box lid), scaling changes the clearance. If you scale down and the lid is too tight, try scaling the lid part only by 100.5–101% in XY axes only (not Z).