Scale conversion FAQ
I get asked the same questions at tournaments and in DMs. Here are the answers, based on what I have measured with calipers and printed myself.
Common conversions
Percentages I use for the most frequent scaling needs.
| From | To | Slicer % |
|---|---|---|
| 32mm (Heroic) | 28mm (True) | 87.5% |
| 1:56 (Bolt Action) | 1:48 (Tamiya) | 116.7% |
| 1:35 (Model Kit) | 1:56 (Tabletop) | 62.5% |
| 32mm (AoS/Legion) | 28mm (D&D) | 87.5% |
| 28mm (Heroic) | 1:48 (True) | 130.4% |
| 1:48 (Aircraft) | 1:56 (Ground) | 85.7% |
All questions
Methodology
Do you measure miniatures to the eyes or to the top of the head?
I measure to the eyes at 160cm on a 175cm human baseline. This is what most of the fantasy and sci-fi hobby uses because helmets, top-knots, and headgear vary. Historical military kits often use top-of-head (175cm). The stlscale converter lets you pick either method.
Why is scale so inconsistent between manufacturers?
Because nobody agreed on where to put the ruler. Some sculptors measure to the eyes, some to the crown. Some account for base thickness, some do not. A "28mm" miniature from 2010 is often smaller than a "28mm" miniature from 2024. I built the 175cm human baseline to cut through the noise and give everyone the same starting point.
Can a 28mm and 32mm miniature be the same physical size?
Sometimes. A 28mm miniature measured to the eyes is roughly 30-32mm to the top of the head once you add the forehead and a helmet. So a "28mm" figure can stand 32mm tall. This is why labels are unreliable. Measure the eye level with digital calipers if you want to know what you actually have.
How do I check scale without printing the whole model?
Import the STL into your slicer and measure the eye height against the 175cm baseline. For a 28mm figure, the eyes should sit at 28mm above the base. For 32mm, 32mm. If the model has a dynamic pose with a raised weapon, measure from the foot contact point to the eyes, not from the lowest point of the bounding box.
Sci-fi and fantasy
Are Primaris Space Marines 32mm or 28mm?
Primaris models are 32mm to the top of the head, which is roughly 28mm to the eyes. This matches the standard 1:56 ratio. They are taller than older "Firstborn" Marines because the legs and torsos are proportioned like a real human, not compressed.
Does '32mm' mean model height or base diameter?
It usually means model height, but Games Workshop also uses 32mm as a base diameter for newer models. Do not confuse the two. A 32mm base is a plastic disc. A 32mm model is the figure standing on it. The stlscale converter handles height, not base size.
Can I use the same STL file for both 28mm and 32mm games?
No. A file designed for 28mm will look like a child next to 32mm figures, and a 32mm file will tower over 28mm ones. You need to scale it. Use 114.3% to go from 28mm to 32mm, or 87.5% to go the other way. The proportions also change: 32mm heroic has bigger heads and hands relative to the body.
How do I mix Necromunda models (32-35mm) with standard 28mm?
Scale the Necromunda models down to 87.5% to match 28mm, or scale your 28mm collection up to 114.3% to match 32mm. Do not mix them without scaling. A 35mm Necromunda ganger next to a 28mm Guardsman looks like a giant. I have made this mistake. It is fixable, but you need to commit to one baseline for the whole force.
Historical and vehicles
What vehicle scale works with 28mm Bolt Action infantry?
Officially 1:56. In practice, 1:48 Tamiya kits often look better because modern Bolt Action plastics are closer to 30-32mm than true 28mm. A true 1:56 tank looks small next to chunky heroic infantry. Try both if you have them. I use 1:48 for my Bolt Action motor pool and nobody has complained at tournaments.
Will 1:48 infantry look too tall next to 28mm figures?
Yes. True 1:48 figures are about 35mm tall. They will tower over 28mm tabletop miniatures. If you have 1:48 figures you want to use, scale them down to 76.8% to match 28mm eye level. Or just use them as officers and heroes who are supposed to be tall.
Why are there so few 1:56 vehicle STLs available?
Most historical vehicle designers work in 1:35 for traditional model kits. 1:56 is a wargaming niche. You can downscale a 1:35 vehicle STL to 62.5% to get a 1:56 equivalent. On FDM the detail may soften at that reduction, but a 0.2mm nozzle helps preserve it.
FDM printing and slicers
Should I scale by bounding box height?
No. A model with a raised sword or horn will have a tall bounding box that has nothing to do with the figure's actual scale. Always measure from foot contact point to eye level. Ignore weapons, banners, and dynamic poses. The stlscale converter uses this foot-to-eye method automatically.
Does FDM filament shrink and affect scale?
PLA and PETG can shrink 0.2% to 0.5% as they cool from printing temperature. This is small enough that it rarely matters for miniature scaling, but if you need maximum accuracy, print a temperature tower and measure the result. I do not add compensation for FDM because over-extrusion and cooling shrinkage tend to cancel each other out.
Can FDM print miniatures at 28mm and 32mm scale?
Yes. FDM at 28mm and 32mm works well with a 0.2mm nozzle at 0.06mm layer height. The detail is good enough for tabletop use. With a 0.4mm nozzle at 0.1mm layers, faces lose definition but armour, weapons, and terrain still look great. I print all my own models on a Bambu Lab A1 Mini with PLA. The percentages on this site match what I get on my own prints.
Which slicer should I use for scale conversions?
Bambu Studio, PrusaSlicer, and Cura all have a uniform scale field. Enter the percentage from stlscale, lock the XYZ proportions, and slice. The math is the same in every slicer. For FDM, check the preview before slicing — supports can add a few millimeters to the bounding box.