FOV Calculator

Convert field of view between horizontal and vertical, and see how a FOV set at 4:3 looks at 16:9, 21:9 or 32:9 — the trigonometry games use, shown.

Field of view

Horizontal FOV at 16:9106.26°90° horizontal and 73.74° vertical at 4:3
16:9
106.3° wide
16:10
100.4° wide
4:3
90° wide
21:9 (64:27)
121.3° wide
32:9
138.9° wide
5:4
86.3° wide
  • tan(horizontal ÷ 2) = tan(vertical ÷ 2) × width ÷ height. With the vertical FOV kept, a wider screen shows more at the sides (Hor+), as most modern games do.
  • Games state FOV differently — horizontal at 4:3, horizontal at 16:9, or vertical — so check which your game’s setting means before copying a number between games.

FOV

Such as 16:9, 4:3 or 2560x1080.
How is this calculated?
tan(horizontal ÷ 2) = tan(vertical ÷ 2) × width ÷ height. On another screen (Hor+): keep the vertical FOV and recompute the horizontal.

Runs in your browser — nothing you enter leaves this device.

About this tool

What it does

FOV Calculator converts a game’s field of view — how wide an angle the screen shows — between the ways games state it. Some measure FOV horizontally, some vertically; some measure the horizontal at 4:3 even on a widescreen monitor. The two are linked by the screen’s shape: the tangent of half the horizontal angle equals the tangent of half the vertical angle times the aspect ratio. Enter a FOV, whether it is horizontal or vertical, and the aspect ratio it was set for, and it gives both angles and what that view becomes on another screen: most modern games keep the vertical FOV and show more at the sides on a wider screen (called Hor+), so a 90° horizontal view at 4:3 is about 106° on 16:9 and about 121° on 21:9. A table shows the horizontal FOV on every common shape at once. Useful when moving to an ultrawide, copying a setting between games, or wondering why the same number looks wider in one game than another.

How to use it
  1. Enter the field of view and whether it is horizontal or vertical.
  2. Enter the aspect ratio it is set for (16:9, 4:3, 2560x1080…).
  3. Choose the screen to see it on.
  4. Read both angles and the table of screens.
Limits and your data
  • It assumes Hor+ scaling; a few older games stretch or crop the picture instead.
  • Games’ settings differ in what they measure; check your game’s documentation before copying a number.
  • Everything is worked out in your browser. Nothing is sent anywhere.

Questions

What is 90 FOV at 4:3 on a 16:9 screen?

About 106.26° horizontal, with the same 73.74° vertical.

What is Hor+?

Keeping the vertical view and widening the horizontal on wider screens, so an ultrawide shows more at the sides.

Does a higher FOV help?

You see more at the sides, but everything looks smaller and the edges stretch. Many players settle between 90° and 110° horizontal.

How do I enter an ultrawide?

Type its resolution, such as 3440x1440, or choose 21:9.