Fleischmann Profi track: how big should your baseboard be?

Benjamin | TrackDrawer.com · published 14 November 2026

For a closed loop in Fleischmann Profi track you need an 85 x 85 cm baseboard, on R1 at 356.5 mm. A loop with a passing loop fits from 165 x 85 cm, and the Auto-designer lays double track on R2 and R1 from as little as 120 x 100 cm. That is down to the small track spacing of 63.5 mm: two loops side by side fit into less depth with Profi than with most other H0 systems.

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

Curves of 36 degrees

Fleischmann Profi track is H0 track for two-rail DC, without a roadbed. What sets it apart is the angle of the curves: a full piece turns 36 degrees, a half piece 18 degrees. Ten full pieces make a circle, five a semicircle. Most other systems work with 30 and 15 degrees.

The radii are 63.5 mm apart each time: R1 356.5 mm (6120 and the half piece 6122), R2 420 mm (6125), R3 483.5 mm (6131, only as a half piece) and R4 547 mm (6133, also as a half piece). The 6138 at 647 mm is the compensating curve for the turnout, not an ordinary curve in the series. The width of the track seen from above is 25 mm in our catalogue; that is an estimate.

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.

Each step costs 12.7 cm of depth. Double track on R2 and R1 therefore fits on a baseboard one metre deep, on R3 and R2 on 110 cm.

The smallest loop: 85 x 85 cm

With 83.8 cm as the lower limit, that becomes an 85 x 85 cm baseboard in 5 cm steps. The designer lays ten R1 curves there with two short 10 mm pieces (6107) in between: 12 pieces and 2.26 m of track. On 100 x 90 cm it becomes an R1 oval with 14 pieces and 2.47 m.

A passing loop: from 165 x 85 cm

The Profi turnout (6170 left, 6171 right) is 200 mm long and diverges at 18 degrees with a 647 mm radius. With the compensating curve 6138 it advances 399.87 mm; on the straight side the 200 mm straight 6101 makes it up to 400 mm. The second track then sits 63.3 mm beside the first, within a few tenths of the 63.5 mm between the radii. A passing loop therefore costs 40 cm at each end.

The Auto-designer found the first loop with a passing loop on 165 x 85 cm: "Station with two platforms on R1, plus 2 sidings", 36 pieces and 5.95 m of track. The same baseboard also takes a station with one passing loop and three sidings, 38 pieces and 6.06 m. At 95 cm deep, 165 cm remained the smallest width. How a passing loop is put together is explained in passing loop: how two trains pass each other.

What fits on common sizes?

What stands out:

• One metre of depth is enough for double track. That makes Profi interesting for a baseboard 120 to 160 cm wide against a wall. How it compares with the other H0 systems on 180 x 90 cm is covered in an H0 layout on 180 x 90 cm.
• On 240 x 120 cm nothing is added. The designer found the same plan there as on 200 x 120 cm. The collection in our measurement has only four straight lengths and few large curves; to fill a bigger baseboard you need more pieces or flexible track. Compare the other systems in an H0 layout on 240 x 120 cm.

Buffer stop, crossings and flexible track

• Buffer stop 6116. A 105 mm end piece. The designer finishes sidings with it; how long a siding should be is covered in sidings and buffer stops.
• Crossings at two angles. The 6160 crosses at 36 degrees and is 105 mm long, the 6162 and 6163 cross at 18 degrees. There is also a three-way turnout (6157) and double slips (6164 and 6165), all with the 18 degree divergence.
• Short pieces. Straights of 200, 105, 100 and 10 mm. With the 10 mm piece you can adjust a loop to the centimetre.
• Flexible track 6106. An 800 mm length for curves of any radius, for example a wide curve along a wall.

Because the curves are 36 degrees, the corners of a plan fall differently than with 30 degree systems. Triangles, rhombuses and hexagons did not appear with Profi in our measurements; ovals, dog bones, stations and double track did.

Frequently asked questions

Why does double track fit in one metre of depth?

Double track on R2 and R1 is 865 mm wide on the outside. With a 5 cm margin on each side that becomes 96.5 cm. In our measurement the designer laid the first double track on 120 x 100 cm, with 32 pieces and 5.76 m of track.

Can I mix Profi curves with 30 degree curves?

Not within the same system: Profi track has no 30 or 15 degree pieces. A loop has to turn 360 degrees in total; with 36 and 18 degree pieces that always works out, and the designer takes it into account.

Your own baseboard

Enter your baseboard and your Profi track and let the Auto-designer lay a plan that fits.