What Is FOV, and Why Are There Three Kinds?
Field of view (FOV) is how much of the game world you can see at once, measured in degrees. The catch is that games don't agree on which angle they're measuring: some report the horizontal spread, some the vertical spread, and some the full diagonal corner-to-corner angle. The same "90 FOV" setting can look completely different between two games simply because they're measuring a different axis - this calculator converts between all three so you can match the feel you're used to.
How to Use This Calculator
- Enter the FOV value shown in your current game.
- Select which type that value is - check your game's settings menu or community wiki if it isn't labeled.
- Enter your resolution's width and height (or its simplified ratio, like 16 and 9).
- Read the equivalent horizontal, vertical, and diagonal FOV instantly.
How the Calculation Works
FOV conversion depends on your aspect ratio because the three angles form a right triangle across the screen. Given a known FOV and the aspect ratio (width ÷ height), the other two are found with:
Horizontal → Vertical: vFOV = 2 × atan( tan(hFOV ÷ 2) ÷ aspectRatio )
Vertical → Horizontal: hFOV = 2 × atan( tan(vFOV ÷ 2) × aspectRatio )
Diagonal is then derived from the horizontal and vertical half-angles combined using the Pythagorean relationship between the two, since the diagonal spans both axes at once.
Understanding Your Result
| Horizontal FOV | Typical Feel |
|---|---|
| 60–75° | Narrow - common console-style default, less peripheral awareness |
| 90–100° | Standard PC competitive default for many shooters |
| 100–110° | Wide - more peripheral vision, slight fisheye distortion at screen edges |
| Above 110° | Very wide - used mostly on ultrawide monitors to avoid a cramped feel |
Benefits and Practical Uses
- Match your FOV feel when switching between games that report FOV differently.
- Set an equivalent FOV after moving from a 16:9 monitor to an ultrawide, or vice versa.
- Understand why a "90 FOV" recommendation from a friend on a different aspect ratio might not match yours.
Common Mistakes to Avoid
- Assuming all games mean the same FOV type - many competitive shooters use horizontal FOV, while several game engines (including Source-based titles) default to vertical.
- Using your monitor's raw pixel resolution when you actually want the simplified ratio - either works mathematically, since only the ratio between the two numbers matters.
Frequently Asked Questions
Does a wider FOV make me a worse or better player?
Neither inherently - a wider FOV gives more peripheral awareness at the cost of making distant targets appear smaller, while a narrower FOV does the opposite. Most players settle on whichever feels natural and doesn't cause discomfort.
Why does my FOV look different after changing my aspect ratio?
Because horizontal and vertical FOV are linked through the aspect ratio - changing your resolution's ratio while keeping the same reported FOV value will visibly change how much you can see on the wider or taller axis.
What FOV do most competitive players use?
It varies by game and genre, but many competitive FPS players on a standard 16:9 monitor land somewhere between 90 and 103 horizontal FOV, largely as a personal comfort preference.
Conclusion
FOV conversion removes the guesswork when a game's settings menu speaks a different "FOV language" than you're used to. Pair this with the Aspect Ratio Calculator if you're also unsure what ratio your current resolution actually simplifies to.