Per BS EN 61537 and manufacturer recommendations: Ladder tray: 3m horizontal, 2m vertical (strong side rails allow wider spacing), Perforated/solid tray: 1. 5m . Cable tray support quantity can be calculated using a simple formula: Support Quantity = Total Length ÷ Support Spacing + 1 20 ÷ 2 + 1 = 11 supports In a typical project, a 20-meter cable tray with 2-meter spacing requires 11 supports. Cable tray supports are components used to fix and support. The right cable tray sizing calculator helps engineers turn cable schedules into a verified tray width and fill check before material ordering and site installation. IEC 61537 covers cable tray and cable ladder systems for the support and accommodation of cables, while NEC Article 392 governs cable. IEC 61537 and IEC 60364 require evaluating tray dimensions based on cable quantity, type, and layout configuration. Below are industry-standard tray and ladder dimensions used globally, based on typical installations and in alignment with IEC 61537:2016 and manufacturer catalogs.