Quick answer: standard round plastic bases for Warhammer 40,000 and Warhammer Age of Sigmar are about 3–4mm tall. Hobbyists who have measured them with callipers usually report somewhere between about 3.2mm and 4.5mm, and some batches differ slightly. The sides slope, so the top is narrower than the stated size. A 25mm base is about 23mm across the top, for example. The underside is hollow, so a magnet or steel disc can sit inside the rim.
Base height rarely matters on the tabletop, but it matters a lot when you magnetise models, build movement trays or display boards, or raise a model with cork and rocks. Here is what to expect and how to measure your own.
Typical round base dimensions
These are approximate figures, collected from hobbyist measurements and basing-supply guides. They are not official specifications, so measure your own bases before you cut or drill anything.
| Stated base size | Approx. top diameter | Approx. height |
|---|---|---|
| 25mm round | About 23mm | About 3–4mm |
| 32mm round | About 29mm | About 3–4mm |
| 40mm round | About 37mm | About 3–4mm |
| 50mm round | About 47mm | About 3–4mm |
| 60mm round | About 56mm | About 3–4mm |
The stated size is the diameter at the bottom edge, where the base meets the table. That is the measurement that counts for most rules on movement and range, so check your current rules for exactly how distances are measured.
Why the top is smaller than the base size
Round bases have bevelled sides that slope inwards, so the flat top surface is a few millimetres narrower than the footprint. This matters when you:
- Cut basing toppers from cork, plasticard or textured sheets. Size them to the top surface, not the stated base size.
- Use pre-made resin or printed base toppers. They are often sized to the top surface, so check before you buy.
- Paint base rims. The bevelled edge gives a neat band to paint in a single colour, which many painters use to frame the model.
Base height and magnets
Because the underside is hollow, there is a shallow recess inside the rim. That is where most people fit a magnet or a thin steel disc.
- Magnet thickness: many hobbyists use magnets around 2mm thick for round bases so they sit inside the recess with little or no wobble. Thicker magnets may stand proud of the rim.
- Flush fitting: if a magnet sticks out, the model can rock on a flat surface. Fit thinner magnets, or recess them slightly with a drill or file.
- Diameter first: a wider, thinner magnet usually gives more grip than a narrow, thick one, and it fits the recess better.
Our guides on what size magnets to use and how to magnetise bases go into magnet sizes and fitting in more detail.
Base height for movement trays and display boards
If you are building trays or boards with recesses for each model, the depth of the recess should be a bit less than the base height so models are easy to lift out. A common approach is to use sheet material of about 2–3mm for the cut-out layer. Leave a little clearance around each base too, because diameters vary slightly between batches and older bases can be a slightly different size from newer ones.
Raised and scenic bases
Many painters build up the top of the base with cork, rocks or sculpted terrain, so the finished base can be much taller than 3–4mm. That is fine for gaming and display, but bear in mind:
- Raised bases change how tall the model stands, which can affect how it looks next to others in the unit.
- Very tall scenic bases can make magnetised models top-heavy.
- Check any event or tournament guidance if you plan to play with heavily modified bases.
How to measure a base accurately
- Use digital callipers if you can. A ruler is fine for diameter but not accurate enough for height.
- Measure the height at the rim, not at the centre, where texture or sand may build up.
- Measure the bottom diameter across the widest point, and the top across the flat surface.
- Measure two or three bases from the same batch, because small differences are normal.
For the base sizes used across different units and models, see our Warhammer 40,000 base sizes guide.
Frequently asked questions
How tall is a Warhammer base?
Standard round plastic bases are about 3–4mm tall. Hobbyist measurements usually fall between about 3.2mm and 4.5mm, with small differences between batches.
How thick is a 32mm base?
About 3–4mm, like other standard round bases. The top surface is about 29mm across because the sides slope inwards.
What thickness magnet fits under a round base?
Many hobbyists use magnets around 2mm thick so they sit inside the hollow underside without making the model rock. Measure your bases first, as recess depth can vary.
Is the base size measured at the top or the bottom?
The stated size, such as 25mm or 32mm, is the bottom diameter where the base touches the table. The top surface is a few millimetres smaller.
Are all round bases the same height?
They are similar, but not identical. Batches and older bases can differ slightly, so measure before building trays or cutting recesses.
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