How to use
- Type the FOV value from your game settings.
- Tell the calculator what it is: horizontal or vertical, and the aspect ratio it belongs to (CS2's 90° is horizontal at 4:3; Valorant's 103° is horizontal at 16:9).
- Read the converted values: vertical FOV, and horizontal FOV at 4:3, 16:9, 16:10 and 21:9.
- Use the result to set the same effective FOV in another game or after switching to an ultrawide monitor.
The formula and a worked example
Field of view is a trigonometry problem: the screen is a rectangle at a fixed distance from the eye, so horizontal and vertical angles are linked through the aspect ratio.
vFOV = 2 × atan( tan(hFOV / 2) × height / width )hFOV = 2 × atan( tan(vFOV / 2) × width / height )
Example — CS2. The game defines 90° horizontally on a 4:3 base. Vertical: 2 × atan(tan 45° × 3/4) = 2 × atan(0.75) = 73.74°. Games with "Hor+" scaling (CS2, Valorant, Apex, Overwatch, Fortnite) keep this vertical angle and widen the picture on wider screens, so on 16:9 the horizontal FOV becomes 2 × atan(tan 36.87° × 16/9) = 106.26°, on 16:10 100.39°, on 21:9 about 120.5°.
Example — Valorant. 103° horizontal at 16:9 → vertical 2 × atan(tan 51.5° × 9/16) = 70.53°. Overwatch 2 at its max 103° gives the same 70.53° vertical. Apex at 110° → 77.55° vertical. Fortnite at 80° → 50.53° vertical, at 120° → 88.5°.
FOV by game — what the slider really means
| Game | Setting | Defined as | Vertical FOV | Horizontal at 16:9 |
|---|---|---|---|---|
| CS2 / CS:GO | fixed (viewmodel only) | 90° horizontal at 4:3 | 73.74° | 106.26° |
| Valorant | fixed | 103° horizontal at 16:9 | 70.53° | 103° |
| Apex Legends | 70–110 | horizontal at 4:3 base, Hor+ | at 110: 77.55° | at 110: ~123°* |
| Overwatch 2 | 80–103 | horizontal at 16:9 | at 103: 70.53° | 103° |
| Fortnite | 80–120 (unlocked) | horizontal at 16:9 | at 80: 50.53°, at 120: 88.5° | 80–120° |
| Rainbow Six Siege | 60–90 | vertical | 60–90° | at 60: 91.5°, at 90: 121.3° |
| Call of Duty | 60–120 | horizontal at 16:9 | at 80: 50.53° | 60–120° |
* Apex reads its slider on a 4:3 base like the Source engine, so "110" on a 16:9 monitor is wider than 110° of actual horizontal view. That is exactly the trap this calculator removes: two games showing "103" and "110" may or may not show the same picture depending on how they define the number.
4:3 stretched vs 16:9 and why it matters
Many CS2 players run 1280×960 or 1440×1080 stretched. The game then renders a 4:3 picture with 90° horizontal FOV — narrower than the 106° a 16:9 native player sees — and the monitor stretches it across the whole screen. Objects look wider, the perceived movement across the screen is faster, and peripheral vision is lost on both sides. Nothing about the sensitivity changes (cm/360 is unaffected by FOV), but the screen distance per degree grows, which is why some players feel stretched "increases sensitivity".
4:3 black bars keep the same 90° image without stretching. 16:9 native gives the widest view. Neither is objectively better; ProSettings lists show top players on all three.
For games with a free FOV slider the trade-off is the same: a higher FOV shows more but makes distant targets smaller (fewer pixels per degree) and adds a fish-eye distortion at the edges above ~110° horizontal. A useful reference is your monitor: at 60 cm from a 27-inch 16:9 screen the display itself covers about 53° horizontally, so any FOV above that compresses the world.
What makes ours different
The calculator asks the one question other pages skip — is your number horizontal or vertical, and on which aspect ratio — because without it the conversion is simply wrong for CS2 and Apex. It prints results for four aspect ratios at once and shows the formula so you can check it. Free, no account, no ad overlay, computed in your browser.
Privacy
The numbers never leave your browser. No requests are made while you use the calculator and nothing is stored.
FAQ
What is the FOV in CS2?
Fixed: 90° horizontal on a 4:3 base, which equals 73.74° vertical and 106.26° horizontal on a 16:9 monitor. The fov_cs_debug command only works offline; viewmodel_fov changes the weapon model, not the world.
What is Valorant's FOV?
103° horizontal at 16:9, fixed for everyone (70.53° vertical). On a 4:3 stretched resolution the game still renders 103° in the aspect of the render target, so the picture simply gets stretched.
How do I match Apex FOV to CS2?
CS2 is 73.74° vertical. In Apex, set the slider so the vertical FOV is the same: since Apex uses a 4:3 base like CS2, slider 90 equals CS2 exactly; most Apex players prefer 100–110 for peripheral vision.
Does a higher FOV change my sensitivity?
Not the cm/360 — a full turn is still the same distance. But each degree occupies fewer pixels, so the crosshair moves across the screen more slowly per centimetre and distant heads are smaller; many players raise sensitivity slightly at higher FOV.
What is the FOV of an ultrawide 21:9 monitor?
For Hor+ games the vertical FOV stays fixed and the horizontal widens: CS2's 73.74° vertical becomes about 120.5° horizontal at 21:9 (CS2 itself supports 21:9). Games that cap horizontal FOV instead will show black bars or crop.
Why does the same FOV number look different in two games?
Because games define "FOV" differently: horizontal at 4:3 (Source engine, Apex), horizontal at 16:9 (Valorant, Overwatch, Fortnite, COD) or vertical (Rainbow Six). Convert both to vertical FOV to compare honestly.
