What desk width do two monitors need?

For two flat 27-inch 16:9 screens in a straight row, allow about 133.5 cm under the assumptions below. A 140 cm desk clears that width check; a 120 cm desk does not. This is a worked geometry example, not a universal minimum: your actual borders, stands, speaker space and layout can change the answer.

A diagonal is not the width. For a flat screen with ratio a:b, visible width = diagonal × a / √(a² + b²). Convert inches to centimeters with × 2.54, then add the border on both edges. Portrait mode swaps the width and height. All screens use the same drawing scale.

For each pair below: 16:9 flat screens, a 0.5 cm border on every edge, a 2 cm gap between monitors, and 5 cm of reserved desk space at each side. Formula: desk width = two visible widths + four border widths + gap + both side margins. The border is an estimate, not a measured product specification.

First decide which space is negotiable. Reduce optional side margins only if speakers and other objects fit elsewhere. Rotating a secondary 24-inch 16:9 screen changes its visible width from 53.1 to 29.9 cm, but increases its height. Stacking saves horizontal space and needs a mount that supports the required height and load. An arm can free the stand footprint; it does not make the screen itself narrower. Keeping one screen or choosing a smaller second screen may be the better answer.

Measure the clear tabletop width between obstructions, then mark each monitor’s outside rectangle with tape or paper. Check where the feet land, keyboard and mouse space, cables and the rear edge. For an arm, check the manufacturer’s clamp or grommet requirements and whether the desk construction permits installation. Desk depth is a separate decision; a width pass cannot establish a comfortable viewing distance. Finally, test the planned positions in the layout tool using your measured borders and margins, and share the configuration if someone else will assemble it.

This front view estimates horizontal space. It does not measure the footprint of a stand, desk depth, arm clearance or load capacity. Check the manufacturer’s exterior dimensions and mounting instructions before buying. Curvature and inward angles need separate measurements; overlapping rectangles do not represent a valid angled setup.