FOV in FPS Games: The Math Behind Field of View Settings

第一人称射击游戏中的 FOV：视野设置背后的数学原理

Field of view (FOV) is one of the most misunderstood settings in FPS games. A lot of players crank it up for “more visibility” without realizing how it actually distorts the image or how it interacts with aspect ratio. I built a calculator to handle the conversions and wanted to share the reasoning behind it. 视野（FOV）是第一人称射击（FPS）游戏中被误解最深的设置之一。许多玩家为了“获得更多视野”而盲目调高该数值，却没意识到它实际上是如何导致图像畸变，或者它与屏幕纵横比之间是如何相互作用的。我制作了一个计算器来处理这些转换，并想在此分享其背后的逻辑。

Horizontal vs. vertical FOV: Most games report FOV as either horizontal or vertical, and this trips people up when comparing settings between titles. Source engine games (CS, TF2) traditionally use horizontal FOV, while Unreal Engine titles often default to vertical FOV. The conversion isn’t 1:1 — it depends on aspect ratio: Horizontal FOV = 2 × arctan(tan(Vertical FOV / 2) × aspect ratio). So a 90° vertical FOV on a 16:9 screen is a very different horizontal FOV than the same 90° on an ultrawide. 水平视野与垂直视野：大多数游戏将 FOV 标注为水平或垂直视野，这使得玩家在不同游戏间对比设置时经常感到困惑。Source 引擎游戏（如 CS、TF2）传统上使用水平 FOV，而虚幻引擎（Unreal Engine）游戏通常默认使用垂直 FOV。两者之间的转换并非 1:1，而是取决于纵横比：水平 FOV = 2 × arctan(tan(垂直 FOV / 2) × 纵横比)。因此，在 16:9 屏幕上的 90° 垂直 FOV，其对应的水平 FOV 与在超宽屏显示器上的 90° 垂直 FOV 完全不同。

Why this matters for competitive play: A wider FOV shows more of the map but shrinks enemy models on screen, which affects flick accuracy and target acquisition. There’s a real tradeoff between situational awareness and precision, and it’s personal — but it helps to know what number you’re actually changing when a game’s slider just says “FOV.” 这对竞技游戏为何重要：更宽的 FOV 能显示更多的地图信息，但会缩小屏幕上的敌人模型，从而影响甩枪精度和目标锁定。在态势感知和射击精度之间存在着真正的权衡，这因人而异——但了解当游戏滑块仅显示“FOV”时你到底在改变什么数值，是非常有帮助的。

Aspect ratio compounds the problem: If you play on an ultrawide or switch between monitors, the “same” FOV number can look and feel completely different. This is the part most in-game settings menus don’t explain at all. 纵横比加剧了这一问题：如果你使用超宽屏显示器或在不同显示器间切换，同一个“FOV”数值看起来和感觉上可能会完全不同。这是大多数游戏内设置菜单完全没有解释的部分。

What I built: I put together a free calculator that converts between horizontal/vertical FOV and adjusts for aspect ratio, so you can match settings across games or monitors without doing the trig by hand: FOV Calculator Pro. Happy to get into specifics on any engine’s FOV implementation in the comments. 我制作了什么：我开发了一个免费的计算器，可以在水平/垂直 FOV 之间进行转换并根据纵横比进行调整，这样你无需手动计算三角函数，就能在不同游戏或显示器间匹配设置：FOV Calculator Pro。欢迎在评论区讨论任何游戏引擎的 FOV 实现细节。