Märklin M Track: how much baseboard does a metal track layout need?

Benjamin | TrackDrawer.com · published 12 November 2026

For a closed loop in Märklin M Track you need a 70 x 70 cm baseboard, with eight curves on the 286 mm Industriekreis. A loop with a passing loop fits from 145 x 70 cm, double track on R1 and R2 from 120 x 105 cm. M Track has only three radii, and you notice that mainly in the depth: if you avoid the tight Industriekreis you quickly need 85 cm, and double track takes 105 cm.

We measured this with the TrackDrawer Auto-designer, using an ordinary collection of M Track and a 5 cm clear margin around the baseboard.

Three radii and a pressed metal base

Märklin M Track is Märklin's oldest three-rail system: rails with a centre stud contact on a pressed metal base, 27 mm wide in our catalogue. There are three radii: the 286 mm Industriekreis (only as a 45 degree piece, 5120), R1 at 360 mm and R2 at 437.4 mm. Two parallel tracks sit 77.4 mm apart, exactly the difference between R2 and R1.

Still have a box of M Track in the attic? How to recognise it, which turnout generations exist and how to combine it with newer track is covered in giving your old box of track a second life. This article is only about space.

Outside size per radius

The outside size of a circle is twice the radius plus the width of the track. For the baseboard we add a 2 x 50 mm margin.

Look at the last row: with R2 you end up just over a metre. Double track on R2 and R1 therefore does not fit on a baseboard 100 cm deep, but it does on 105 cm. M Track has no further radii in our catalogue.

The smallest loop: 70 x 70 cm

With 69.9 cm as the lower limit, that becomes a 70 x 70 cm baseboard in 5 cm steps. The designer joins eight 5120 curves there: 8 pieces and 1.80 m of track, with no room for straights.

On R1 you need 85 cm of depth. On 100 x 90 cm the designer laid a rhombus on R1 with 18 pieces and 2.59 m of track, or an oval on R1 with 16 pieces and 2.54 m.

A passing loop: from 145 x 70 cm

The most recent M Track standard turnout (5203 left, 5204 right) is 180 mm long and diverges at 24°17' on the R2 radius. The compensating curve 5206 is an R2 curve of the same angle, and on the straight side a 180 mm straight 5106 makes up the length. Turnout and curve together advance 359.8 mm, the straight side 360 mm: a difference of 0.2 mm per turnout end, which disappears in the rail joints.

At 70 cm deep the designer found the first plan with a passing loop from 145 cm wide: "Station with two platforms on the Industriekreis, plus 2 sidings", 30 pieces and 4.98 m of track. At 80 cm deep, 145 cm remained the smallest width. How a passing loop is built and why it needs a long straight is explained in passing loop: how two trains pass each other.

What fits on common sizes?

What this tells you:

• Up to 1 m deep you get one loop. At 100 cm deep the designer places stations, sidings and yards within a single loop, but no second loop. How M Track compares with the other H0 systems on 180 x 90 cm is covered in an H0 layout on 180 x 90 cm.
• From 105 cm deep, double track appears. Already at 120 cm wide, two full loops on R2 and R1 fit.
• A bigger baseboard does not always give more track. On 240 x 120 cm the designer found 9.05 m with this collection, less than the 9.73 m on 200 x 120 cm. The designer works with what is in your inventory: to fill a larger baseboard you also need more straights and turnouts.

The M Track Industriekreis

At 286 mm, the M Track Industriekreis is a little tighter still than that of K Track (295.4 mm). It makes small layouts possible, but long coaches overhang the track a lot in it, and not every locomotive gets through. Which radius your rolling stock can handle is stated by its manufacturer. If you set a minimum radius of 360 mm in the Auto-designer, the smallest loop starts at 85 cm deep and a station with two platforms on R1 fits on 180 x 90 cm.

Handy pieces

• Short straights. M Track has straights of 180, 90, 70, 45, 33.5 and 22.5 mm, plus the filler pieces 5210 (16 mm) and 5208 (8 mm). With these you can close a loop to within a few millimetres.
• Curved turnouts. The 5141 and 5142 split an R1 curve into R1 and R2, 77.4 mm apart. They work like the C Track curved turnouts we explain in Märklin C Track curved turnouts. The Auto-designer uses them when they are in your inventory.
• R1 turnouts from older generations. The 5118 and 5119 (30 degrees) and the 5138 and 5139 (22°30') diverge on R1 instead of R2. In a siding or yard they are compact; for a passing loop at 77.4 mm spacing, use the 5203 and 5204.

Frequently asked questions

Can I combine M Track with K Track or C Track?

Yes, they are all Märklin three-rail AC systems. Between K Track and M Track there is the transition track 2291. The geometry does differ: R1 is 360 mm in all three, but R2 and the track spacing are different in K Track.

Why does double track need 105 cm of depth?

Double track on R2 and R1 is 901.8 mm wide on the outside. With a 5 cm margin on each side that becomes 100.2 cm, just too much for a one metre baseboard. A narrower margin works, but then the track runs close to the edge of the board.

Your own baseboard

Enter your baseboard and your M Track and let the Auto-designer lay a plan that fits.