Setting the angle
Nobody can read a protractor off a monitor stand, and you do not need to. Every method below is one tape measure and one number.
For the sims in the first group below there is no wrong angle. Tell the game the angle you actually have and the picture comes out right either way. The suggested figure is about comfort, not correctness: it puts all three panels the same distance from your eye so nothing stretches or shrinks toward the edges. Within a few degrees is fine.
Sims that render three views
These build a separate camera for each panel, so the angle you set is the angle they draw. Give them the physical layout and the geometry comes out right at every point on the screen.
Sims that render one wide view
One flat image spread across all three panels. Nothing in the game knows your side screens are turned in, so there is no angle or bezel field to find. The number below is the best single compromise, matched exactly on the centre panel and progressively off toward the outer edges.
No triple handling at all
These run on a Surround or borderless span and stretch one frame across the lot. Some expose a FOV slider in unlabeled units, so there is nothing reliable to compute.
How the numbers are found
The eye sits at the origin looking down +z. The centre panel is a curve of
radius R with its vertex at your measured distance, so its edges sit
R(1−cos(w/2R)) closer to you than its middle, which is why a
1000R panel reads a couple of degrees wider than a flat one of the same size.
Side panels hang off the seam: centre bezel, side bezel, then the panel's own
chord turned by your angle.
Vertical FOV is 2·atan(h ÷ 2d) from the centre panel
alone. It does not change between single and triple, which is the part people
most often get wrong.
Horizontal FOV comes in two flavours. The true angle is what your panels physically subtend as installed. The flat-equivalent is what a game rendering one wide viewport needs: the array unfolded into a single plane, pinned 1:1 at the centre panel's edges. Turning your screens in does not change that second number, because the render is flat either way.
Assumptions worth knowing
The model list carries the true viewable diagonal, not the size class on the box. They differ more often than you would think: an LG 42" C-series OLED is 41.5 inches, a Samsung Odyssey G7 "32-inch" is 31.5, and most 49-inch super-ultrawides are 48.8. Every entry was checked against a manufacturer spec sheet or an equivalent source, and anything that could not be pinned down was left out rather than guessed at. Diagonals are treated as arc length along the glass on curved panels, which is how they are specified.
Bezel widths are the one number the list guesses at. Manufacturers rarely publish them and they change between revisions, so the value that arrives with a model is a size-class estimate. Measure yours: it takes ten seconds with a ruler and it feeds the corner-to-corner target directly.
Bezel is measured from the edge of the lit area to the outside of the chassis, one side. A seam is two of them. If you run a bezel-free kit with overlapping panels, enter a negative-ish small value or just zero.
The suggested angle places every panel as a chord of one circle centred on your eye, so all three panel centres sit the same distance away. It is a starting point, not a law; most people end up within a few degrees of it.
Where a title's FOV axis could not be confirmed against an official source, the card says so rather than guessing. Treat unverified values as a place to start and check by eye against a known landmark in the cockpit.