Calculate horizontal, vertical, or compound cable tray offsets based on bend angle, offset distance, and available installation space. The cable support lengths and fittings can basically be designed as cable trays, cable ladders or mesh cable trays, in which cables are routed. Cable ladder systems and cable tray systems shall be manufactured in accordance with BS EN 61537, channel support. 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.