FOV Calculator & Converter
Convert your field of view between 16:9, 4:3, 21:9 and more, see horizontal & vertical FOV, degrees per pixel, and the exact mouse-match factor when you change aspect ratios.
- Runs in your browser
- Free · No sign-up
- 6 aspect ratios
FOV calculator tool
How FOV conversion works
FOV is an angle; aspect ratio changes what it means. If a game fixes vertical FOV,
the horizontal FOV for aspect ratio r is:
hFOV = 2 × atan( tan(vFOV ÷ 2) × r )
The screen-space match factor between two setups (keeping the same on-screen mouse feel near the crosshair) is the ratio of the tangents of their half horizontal FOVs:
factor(source → target) = tan(hFOV_target ÷ 2) ÷ tan(hFOV_source ÷ 2)
Example: 16:9 → 4:3 gives 0.750. CS players apply exactly this by setting
m_yaw 0.0165 (= 0.022 × 0.75) when they play 4:3 stretched, keeping horizontal and
vertical screen speed identical. Read the other way, the horizontal image appears
1.333× wider, the "stretch factor" you see quoted in resolution guides.
Vertical → horizontal FOV reference
| Vertical FOV | Horizontal @ 16:9 | Horizontal @ 4:3 | Horizontal @ 21:9 |
|---|---|---|---|
| 60 | 91.5° | 75.2° | 106.8° |
| 70 | 102.4° | 86.1° | 117.1° |
| 80 | 112.3° | 96.4° | 125.9° |
| 90 | 121.3° | 106.3° | 133.6° |
| 103 | 131.8° | 118.4° | 142.4° |
Calculated with the formula above; verify game-specific behaviour in the calculator.
Frequently asked questions
What is FOV in games?
FOV (field of view) is the angle of the virtual camera, how much of the world you see on screen. A higher FOV shows more of the scene but makes targets look smaller; a lower FOV zooms in for precision but narrows your peripheral vision.
Why does FOV change when I change resolution or aspect ratio?
Most games keep the vertical FOV fixed, so widening the aspect ratio (16:9 → 21:9) widens the horizontal FOV automatically. If a game fixes horizontal FOV instead, ultrawide users get a cropped vertical view. This calculator shows both so you know which definition a game is using.
What FOV do pro FPS players use?
It varies by game and is often set by tournaments. Common conventions: Overwatch 2 103, Apex Legends 104–110, Counter-Strike 2 90–95 (4:3 stretched users often keep 90), Valorant has a fixed 103 horizontal. Always check your league rules.
Does FOV affect sensitivity?
Turning distance (cm/360) is unaffected by FOV. Perception of speed is not, a high FOV makes the world move past faster at the same sensitivity. When pros say "FOV changes your aim," they mean perception and target size, not the rotation maths.
What is the screen-space match factor?
It is tan(hFOV_target ÷ 2) ÷ tan(hFOV_source ÷ 2), the multiplier you apply to your sensitivity when changing aspect ratio to keep the same on-screen mouse feel at the crosshair. For 16:9 → 4:3 it is 0.750, which is why 4:3 stretched players use m_yaw 0.0165 (= 0.022 × 0.75). See the worked example in the "How FOV conversion works" section.