Work out the geometrically correct field of view for sim racing from your monitor size, aspect ratio and eye-to-screen distance, with the value to enter in iRacing, ACC, AC, AMS2 and LMU.
| Input | Result |
|---|---|
| 27" · 16:9 (standard) · 60 cm · 1 screen | 31.3° vertical · 53.0° horizontal · 53° span · panel 59.8×33.6 cm |
| 34" · 21:9 (ultrawide) · 70 cm · 1 screen | 27.3° vertical · 59.1° horizontal · 59° span · panel 79.4×34.0 cm |
| 32" · 16:9 (standard) · 65 cm · 3 screens | 34.1° vertical · 57.2° horizontal · 172° span · panel 70.8×39.8 cm |
Sim racing has two competing conventions for the same setting, and entering the right angle into the wrong one is the most common way to end up with a distorted view. The table below lists only the titles where several independent sources agree on the convention.
| Simulator | Uses |
|---|---|
| iRacing | Horizontal FOV |
| Automobilista 2 | Horizontal FOV |
| Assetto Corsa | Vertical FOV |
| Assetto Corsa Competizione | Vertical FOV |
| Assetto Corsa EVO | Vertical FOV |
| Le Mans Ultimate | Vertical FOV |
Some converters publish a figure for every title regardless of whether the convention is actually settled. We do not. For the following, sources contradict each other, so use the per-screen angle above and check it against a known reference, most usefully the width of your virtual steering wheel against your real one.
Everyone who sets a geometrically correct FOV for the first time thinks it is wrong, because it looks like looking through a letterbox. It is correct. A 27-inch monitor at arm’s length genuinely occupies only about 53° of your horizontal vision; a 90° setting is showing you the world through a fisheye lens and charging you lap time for it.
The fix is not to widen the FOV. It is to move the screen closer, buy a bigger panel, or add side screens, all of which increase the angle the display genuinely subtends, rather than pretending it does.
The geometrically correct field of view is the angle your monitor subtends at your eyes, worked out from the panel's physical width and height and how far away you sit. It is the value that makes the virtual world appear at real-world scale. Anything wider is a fisheye effect: objects look smaller and further away than they are, which pushes your braking point later than it should be.
Whichever your simulator asks for, they are different conventions and a number from one is not valid in the other. iRacing and Automobilista 2 use horizontal FOV. Assetto Corsa, Assetto Corsa Competizione, Assetto Corsa EVO and Le Mans Ultimate use vertical FOV. This page prints both so you can copy the right one.
Because a wider-than-correct FOV distorts distance judgement. The screen shows you more of the track, but everything in it is compressed, so corners arrive looking further away than they are and you brake too late. The gain in peripheral awareness costs more in consistency than it returns.
Because sources disagree about which convention those titles use. Several converter sites publish a figure for them anyway, but where we cannot confirm the convention from more than one independent source we would rather say so than hand you a number that may be wrong. Use the per-screen value above and verify in sim, or check the title's own settings documentation.
Sit in your normal driving position with the seat and wheel where you race, then measure from between your eyes to the centre of the screen. Do not estimate it from arm's length, the distance is the single biggest driver of the result, and a few centimetres of error moves the angle noticeably.
Most sims want the per-screen angle, not the combined span, even on triples, the engine handles the geometry of the side panels once you tell it the angle they are turned in at. Where a title asks for a combined figure, the span shown above is a flat upper bound; angling the side screens inward reduces the true effective span below it.
Only if your screen fills the same portion of your vision, which for a single monitor sitting on a desk it does not. That is exactly why a geometrically correct FOV on a small screen looks narrow: it is honest about the angle the panel actually occupies. Moving the screen closer is the cheapest way to widen it without lying to your eyes.