Sim Racing FOV Calculator
Enter your screen size, resolution and eye distance to get the mathematically correct FOV for your rig. Single screens, ultrawides and triples supported, with per-game notes for iRacing, ACC, LMU, rFactor 2 and more.
- Runs in your browser
- Free · No sign-up
- Correct-geometry formula
FOV calculator tool
Everything is calculated locally in your browser. Nothing you enter is uploaded.
How sim racing FOV is calculated
Your monitor is a window. For the sim to show what you would see through that window, the camera angle must equal the angle the screen physically subtends:
hFOV = 2 × atan( screen width ÷ (2 × eye distance) )
The vertical FOV comes from the aspect ratio:
vFOV = 2 × atan( tan(hFOV ÷ 2) ÷ aspect ).
Screen width is derived from its diagonal and aspect ratio (Pythagoras).
These are the same formulas used across sim racing (and standard perspective projection in
computer graphics); we publish the exact equations on the methodology page.
Where to enter the FOV, per game
Quick orientation: most sims use either a horizontal, vertical or single "FOV" value, and some hide it behind a slider range. Always enter the number shown by the calculator for the axis your game uses, and check our per-game notes below.
| Sim | What the game calls it | Enter |
|---|---|---|
| iRacing | FOV (vertical-angle style value in the graphics options / camera) | Use the value iRacing's own field accepts; check its calculator dialog or set via the in-sim FOV dialog |
| Assetto Corsa (AC) | FOV (horizontal degrees in most camera modes) | Horizontal FOV |
| Assetto Corsa Competizione (ACC) | FOV (single value, horizontal in the usual workflow) | Horizontal FOV |
| Le Mans Ultimate / rFactor 2 | FOV, set per axis in the config | Match the axis your config reads; usually horizontal |
| Automobilista 2 | FOV (vertical in the built-in calculator) | Vertical FOV |
| F1 23–25 | FOV on a slider (-20 to +20 style scale) | The number must be mapped to the slider scale; check our guide |
| GT7 | FOV slider (unitless) | Match visually to the horizontal value; exact mapping varies |
Sim UIs change between patches: if in doubt, put the calculator's value into the axis you can find and verify by comparing a straight road's apparent width against the windshield frame.
Frequently asked questions
What is the correct FOV for sim racing?
The FOV that makes the screen window match the angle you would see through it in a real car: hFOV = 2 × atan(screen width ÷ (2 × eye distance)). For a 27" monitor (60 cm wide) at 60 cm viewing distance that is about 53°. Anything higher is a preference, not a correct value.
Why does my FOV need to change when I move my seat or screens?
FOV is a projection of your real geometry. Move the screens closer and they subtend a wider angle (higher FOV); move further away and it narrows. The calculator only needs your physical measurements, so it stays correct for any rig.
Should I use vertical or horizontal FOV in my sim?
It depends on the game: iRacing takes a vertical-angle style value, ACC and AC show a single "FOV" (horizontal in AC, configurable); rFactor 2 and LMU let you set either. The calculator gives you both numbers, plus a per-game note on which to enter.
What about triple screens?
Triples need two numbers: the per-screen FOV (same formula as a single screen) and the total rig FOV, which also depends on the angle of your side screens. The triple screen calculator handles the full rig, including bezel gaps.
Is a higher FOV better for lap times?
No, and a too-high FOV hurts: it distorts the image, makes braking points harder to judge, and breaks the depth cues your brain expects. Most quick sim racers run FOV close to the mathematically correct value and adapt their sense of speed instead.
Does this work for ultrawide monitors?
Yes. Treat the ultrawide as a single screen using its physical width and enter your aspect ratio; the calculator solves both FOV axes. Note that the larger physical width at the same distance means a wider FOV than a 16:9 screen in the same spot.