To scale terrain from 28 mm to 32 mm, enlarge every axis uniformly to 114.3%. To take a 32 mm model down to 28 mm, use 87.5%. Those figures are the clean mathematical conversions, but the best terrain size still depends on your miniatures’ bases, poses, proportions, and need for playable interior space.
The labels 28 mm and 32 mm commonly refer to the height of an average human figure from its feet to eye level rather than its base diameter. They are working conventions, not tightly standardized measurements. A bulky or “heroic” 28 mm figure may stand beside a slimmer 32 mm figure without looking noticeably smaller. Published terrain guidance similarly treats roughly 1:62 for 28 mm and 1:54 for 32 mm heroic terrain as useful conventions rather than universal rules.
Use these percentages as the starting point
| Conversion | Uniform slicer scale | Example result |
|---|---|---|
| 28 mm terrain to 32 mm | 114.3% | A 30 mm doorway becomes about 34.3 mm wide |
| 32 mm terrain to 28 mm | 87.5% | A 40 mm walkway becomes 35 mm wide |
| 32 mm terrain for a mixed collection | 90% as a possible compromise | A 40 mm walkway becomes 36 mm wide |
The conversion is simply target size divided by original size, multiplied by 100. For 28 mm to 32 mm, that is 32 ÷ 28 × 100 = 114.3%. The reverse calculation is 28 ÷ 32 × 100 = 87.5%. Enter the percentage for X, Y, and Z together in the slicer. Scaling only the width or height can distort arches, stairs, roof pitches, sockets, and decorative details.
The 90% option is not an exact conversion. It is a practical compromise suggested for printing terrain authored at 32 mm when a collection contains both 28 mm and 32 mm figures. It reduces the footprint while retaining more clearance than a strict reduction to 87.5%.
Check physical fit before trusting the label
Doors provide a quick visual check, but they are only the beginning. Put representative miniatures beside a sliced doorway, stair flight, balcony, battlement, corridor, and interior room. Include the broadest base and most exaggerated pose you expect to use. A doorway can look correct while a raised sword catches the lintel or a 32 mm base fails to turn on a landing.
Pay particular attention to the spaces where players handle figures. Larger terrain generally offers more room on stairs, elevated platforms, and inside buildings, while smaller terrain consumes less table area and can look better proportioned beside genuinely 28 mm figures. Practical clearance at these features is more informative than the scale printed in a product description.
- Door height and width: Check the figure, base, weapons, banners, and other projections.
- Stairs and ladders: Confirm that bases can rest securely rather than balancing across several steps.
- Corridors and interiors: Leave enough finger room to place and remove miniatures during play.
- Balconies and battlements: Check both base clearance and railing height.
- Walkways and bridges: Test whether two figures must pass each other or only stand in single file.
- Furniture and props: Avoid enlarging every loose object automatically; an oversized chair is more conspicuous than a slightly generous doorway.
Keep modular terrain together as one system
Scale every connected part by the same percentage. That includes walls, floors, roofs, doors, clips, pegs, sockets, connectors, and separate stair modules. Changing the visible building while leaving its clips at 100% will alter the mechanical fit.
This matters when terrain files are split across several build plates. Record the chosen scale in the project name or slicer notes, then apply it to every plate. Print one connection pair before committing to a settlement-sized batch. Even with correct scaling, first-layer spread and printer calibration can affect tight sockets.
Freestanding scatter terrain is more forgiving. Rocks, ruins, trees, crates, and rubble naturally vary in size, so they can often serve both collections without rescaling. Reserve exact conversion for architecture and game features whose dimensions control movement or access.
Separate miniature scale from the game grid
Figure height, terrain dimensions, and grid distance are related design choices, but they are not the same measurement. The Dungeons & Dragons Basic Rules, for example, define a combat-grid square as representing 5 feet without requiring one particular physical square size for a map or terrain tile.
If your table uses 25 mm, one-inch, or another grid pitch, preserve that pitch unless you intend to rebuild the complete board system. Enlarging a gridded 28 mm tile to 114.3% also enlarges its squares. That may suit larger bases, but it can stop the tile from matching existing mats, walls, or dungeon pieces. In that situation, keep the grid and connection geometry fixed while selectively modifying doors or other cramped features in the model editor.
Adjust the FDM profile after scaling
Scaling changes more than the outside dimensions. At 114.3%, walls, rails, and relief textures become thicker, and bridges become longer. At 87.5%, small gaps narrow, pegs shrink, and fine stone or wood textures move closer to the printer’s XY resolution limit.
For a 0.4 mm nozzle, the Prusa layer and perimeter guidance identifies 0.15 mm and 0.20 mm as practical starting layer heights that balance detail and print time. A 0.10 mm layer can improve Z-axis detail, although it costs more time. Finer layers will not recover every narrow XY detail because nozzle diameter and extrusion width still limit those features. For a deeper look at that distinction, see how line width differs from layer height.
A 0.20 mm layer height is a sensible first test for ordinary stone walls and large buildings. Use finer layers on shallow roof curves, rounded towers, or decorative slopes where visible stepping matters. Variable layer height can put finer layers on those surfaces while leaving simple vertical walls coarser.
Inspect arches, windows, balconies, and broad roofs in the slicer after changing scale. Short bridges are generally easier to print reliably, while rotating a part may reduce unsupported areas at the cost of moving layer lines onto a more visible face. The UltiMaker design guidance for FDM printing provides a useful orientation framework for these tradeoffs.
For large terrain, add walls before reaching for very dense infill. Perimeters contribute substantially to part strength, while infill mainly supports top surfaces and defines the internal structure. The appropriate wall count depends on nozzle size and line width; choosing walls for an FDM print explains how to make that decision.
Print one representative test before the full set
Once the geometry works, print the full set with the same saved scale and profile. Primer and paint can soften the appearance of ordinary FDM layer lines, so a successful terrain test does not need to look resin-smooth straight from the bed. A careful FDM terrain finishing and painting workflow can preserve stone, timber, and rubble texture while unifying the surface.
Start at 114.3% or 87.5%, but let the physical game piece make the final decision. If the miniatures fit through the doors, stand securely on the stairs, move comfortably through the interiors, and remain compatible with the rest of the board, the terrain is at the right working scale.