What the result actually measures
The angle your screen really covers from where your eyes are: 2 × atan(half the screen width ÷ distance). A curved screen is treated as an arc of its radius, and triple screens as the centre screen turned about your eyes by its own angle, so each side screen begins where the centre one ends. The result is then written in each game’s own unit.
Measurement boundary: This is the geometrically correct view, not a rule. Some drivers widen it for awareness at the cost of judging speed and distance. Game units change between versions; if a value looks wrong in a new release, compare it with the game’s own FOV readout.
How to interpret the output
Horizontal or vertical
iRacing, Automobilista 2 and the truck simulators take the horizontal angle; Assetto Corsa, ACC, rFactor 2 and Le Mans Ultimate take the vertical one. The same view gives two very different numbers, which is why a value copied from another game looks wrong.
Why the correct view feels narrow
On a 27-inch screen at 70 cm the correct horizontal view is under 50°, far narrower than the 90° or more many games start with. The car then appears at its real size, and speed and braking distances read as they would from a real seat.
Side screen angle
With three screens, each side screen turns by the same angle the centre one covers. Set that angle in the game wherever it asks, and angle the screens on the desk to match.
Troubleshooting unexpected results
The view looks zoomed in
That is the correct view at a normal desk distance. Move the screen closer to widen it for real, or use a bigger screen; widening the FOV in the game only shrinks everything instead.
The game will not accept the value
Some games limit the range. The table marks values at the game’s limit; there, move the screen closer or accept the nearest value the game allows.
Frequently asked questions
What FOV should I use in iRacing?
The horizontal value from the calculator for your screen and seating distance. For a 27-inch 16:9 screen at 70 cm that is about 46°.
Does ACC use horizontal or vertical FOV?
Vertical. Assetto Corsa and Assetto Corsa Competizione both take the vertical angle, so their number is much smaller than iRacing’s for the same screen.
How do F1 23, F1 24 and F1 25 FOV sliders work?
The slider counts steps from 77° horizontal, 2° per step, between −20 and +20. The calculator gives the step, so a correct view on a desk screen is usually well into the negative numbers.
How far should the wheel rotate?
Twice the car’s front wheel lock times its steering ratio: 480° lock to lock for a 12:1 ratio with 20° of lock. Many sims set this per car when the wheel base is at its full range.
