Platform Length Calculator — Station Planning

Ideally, the platform should be slightly longer than your longest train. In OO gauge, a 4-coach train with loco is about 1280mm. If space is limited, a selective compression platform at 70% of train length still looks acceptable.

The UK full-size standard is 915mm above rail level (Network Rail / RSSB). Scaled down, that is about 12mm in OO (1:76.2), about 6mm in N (1:148) and about 21mm in O (1:43.5). The platform face should sit roughly 2mm clear of the carriage side so stock does not foul it.

Selective compression means making the platform shorter than scale length while keeping it looking correct. A platform at 70% of train length looks fine because viewers focus on the train-platform interface, not the exact length match.

Platform ends taper down to track level on a gentle ramp. Model this at a 1:8 slope (rise:run), the maximum allowed on full-size platforms per the HSE Railway Safety Principles. For OO gauge with a 12mm platform height the ramp is about 96mm long (12 × 8); in N (6mm) about 48mm. Use card, balsa, or a commercial platform-ramp kit.