Quick Method to Determine Correct Tray Size: Cable Tray Size Calculation: Step-by-Step Guide with Formula and Example The basic formulas used in a sizing calculator are straightforward: Fill % = (Total Cable Area / Tray Area) × 100 Tray Area = Width × Usable DepthQuick Method to Determine Correct Tray Size: Cable Tray Size Calculation: Step-by-Step Guide with Formula and Example The basic formulas used in a sizing calculator are straightforward: Fill % = (Total Cable Area / Tray Area) × 100 Tray Area = Width × Usable DepthCalculate horizontal, vertical, or compound cable tray offsets based on bend angle, offset distance, and available installation space. Use this tool to estimate sloped section length, horizontal run requirement, cut marks, and installation feasibility. Choose which known dimensions you want to use for calculating the offset tray geometry. Note: It is best practice to. Hubbell's NEXTFRAME® Ladder Tray is the effective and widely used cable runway that supports and delivers bundles of cable between cabinets, racks, and closets, along walls, and suspended from ceilings. The Ladder Tray features light, rugged, tubular steel construction. 9 (B), when using ventilated tray with multi conductor control cable, the sum of the cross sectional areas shall not exceed 50 percent of the interior cross section of the cable raceway / tray.