H0, N, TT or Z: which scale fits your space?

Benjamin | TrackDrawer.com · published 31 October 2026

The smaller the scale, the more layout you fit on the same baseboard. A closed loop with a passing track needs at least 160 x 90 cm in H0, but only 85 x 55 cm in N: about a third of the area. TT sits in between, Z goes smaller still. What you choose depends on your room, but also on how you want to play and how well you can see and handle small things.

Four scales side by side

A scale is the ratio between model and prototype. The gauge follows from it: standard gauge of 1435 mm is reduced in every scale.

• H0, scale 1:87, gauge 16.5 mm. The most widespread scale in Europe, with the largest range.
• TT, scale 1:120, gauge 12 mm. An in-between size, especially strong in Central and Eastern Europe.
• N, scale 1:160, gauge 9 mm. Popular with anyone who wants a lot of layout in little space.
• Z, scale 1:220, gauge 6.5 mm. Very small, it even fits in a suitcase or on a shelf.

How much baseboard do you need per scale?

To compare the scales we measured per track system with the TrackDrawer Auto-designer. Each time with a typical stock (per radius a full circle plus a few curves, straights, three left and three right turnouts, reverse curves and compensation pieces) and a 5 cm clear edge all round. The board grows in steps of 5 cm. "Smallest loop" is the smallest square board with a closed loop, "with passing loop" the smallest board that takes a loop with at least one passing track.

Even within N the sizes differ. Kato Unitrack N lays a loop with a passing track on 115 x 60 cm, 30 cm wider than Minitrix: the smallest radius is larger, and the turnout with its compensating curve takes up 249 mm along the track, against 158 mm for Minitrix.

The smallest radius comes from our catalogue and is measured to the track centre. Systems of the same scale differ: Piko A-Gleis has the same smallest radius as Märklin C track, but a wider roadbed and different turnout geometry, and the designer needed 25 cm more width there for a passing loop. So look at your own system, not just at the scale. For Märklin C track the full detail is in how much space you need for C track.

What the area tells you

Convert the board sizes to area and the difference becomes tangible. A loop with a passing track in H0 on 160 x 90 cm takes 1.44 m². The same set-up in N with Minitrix fits on 85 x 55 cm, or 0.47 m². That is about a third.

Turned around: on a 180 x 90 cm board, a common size for a first H0 layout, H0 gives you an oval with a passing loop or a small station. In N the same board is more than three times what a loop with a passing track needs: room for more tracks, a larger station or scenery beside it. What fits in H0 at that size is in an H0 layout on 180 x 90 cm.

Trains scale down too, and so do stations

Not only the curves get smaller, the trains do as well. That matters at least as much, because the length of your trains sets the length of your platforms, passing loops and storage sidings.

Take a common European coach 26.4 m long. In each scale that becomes:

An N train is therefore about 54 percent as long as the same train in H0 (87 divided by 160 is 0.54). A station with platforms for four coaches already needs over 1.2 m of straight in H0, without the locomotive and without the turnouts at both ends. In N it is 66 cm. That is often the real argument for a smaller scale: not the curve, but the station.

If you build H0 on a small board, you often choose shorter trains: a locomotive with two coaches, or a short goods train. That is no drawback, as long as you decide it up front.

Visibility and handling

Space is not the only criterion. A few things to weigh:

• Seeing. In H0 you can make out details on locomotives and wagons from a normal distance. In N and certainly in Z a train becomes more a part of the landscape. Some people prefer exactly that, others miss the detail.
• Handling. Putting a wagon on the track, coupling and uncoupling are easier by hand in H0. In the smaller scales you more often use a rerailer.
• Clean track. Smaller and lighter models usually have less weight on their wheels. They therefore often need somewhat cleaner rails for good electrical contact.
• Range. In Europe, H0 has the widest range of trains, buildings and accessories. In TT and Z the choice is smaller, although that varies by country and era.

If you build with children or mainly want to play, a larger scale is often handier. If you mainly want scenery with long trains on a limited board, a smaller scale wins. If you pick an era, also check that your scale offers enough stock for it: see eras I to VI.

Rules of thumb per scale

• Less than 1 m² free: N or Z for a layout with a passing loop, or H0 with a simple loop.
• A 180 x 90 cm board: H0 with an oval, passing loop and small station, or N with an extensive plan.
• 200 x 120 cm or more: H0 with a double track and a yard becomes possible.
• A shelf or windowsill: Z or N, perhaps as an end-to-end line without a loop.

With every system you also choose your radius. A larger radius looks calmer and suits long models better, but every step costs depth. In H0 with C track that is 15.5 cm per step (2 x 77.5 mm), in N with Minitrix 6.7 cm (2 x 33.6 mm).

Frequently asked questions

Can I change scale later?

Track and trains are not interchangeable between scales, so in practice you start again. You can keep your plan as an idea, though: you do not convert an H0 plan one to one, but the layout concept (loop, passing loop, station) stays useful.

Is TT a good middle way?

For space, yes: trains are about 73 percent of their H0 length, and the smallest radius in our catalogue is smaller than in H0. Do check whether the TT range matches what you want to run.

Try it with your own size

Enter your baseboard size, pick a system in the scale you are considering and let the Auto-designer lay out plans. You will see straight away what fits on the same board in H0 and in N.