Skip to content
Kordu Tools

FOV Calculator

Calculate and convert field of view between horizontal, vertical, and diagonal FOV for any aspect ratio. Includes game presets for CS2, Valorant, Apex, and more.

Calculated FOV values

Horizontal FOV

90.00°

Vertical FOV

58.72°

Diagonal FOV

97.85°

FOV visualization (HFOV)

90.00°

Recommended FOV for 16:9

90° – 110°

The standard competitive range. Lower values help with long-range aim, higher values improve peripheral awareness.

FOV conversion uses the tangent-based formula that accounts for aspect ratio geometry. Game presets use HFOV values. Some games display VFOV in their settings — check your title's documentation if results seem off.

How to use

  1. 1

    Enter your FOV value

    Type your current horizontal or vertical field of view into the input field, or click a game preset to auto-fill a common value.

  2. 2

    Select your aspect ratio

    Choose from preset aspect ratios (16:9, 21:9, 4:3, 16:10) or enter a custom width and height ratio to match your monitor.

  3. 3

    Choose the conversion direction

    Switch between HFOV to VFOV or VFOV to HFOV mode depending on which value you already know.

  4. 4

    Read your results

    View the calculated horizontal, vertical, and diagonal FOV values along with a visual diagram showing the field of view angle.

Frequently asked questions

What is the difference between horizontal and vertical FOV?
Horizontal FOV (HFOV) is the angle of your visible game world measured left to right. Vertical FOV (VFOV) is the angle measured top to bottom. Most games let you set one and calculate the other from your aspect ratio, though which one they expose varies by title.
Why does aspect ratio affect FOV?
A wider aspect ratio (like 21:9) shows more of the world horizontally for the same vertical FOV. The mathematical relationship between HFOV and VFOV depends on the width-to-height ratio of your display, so changing aspect ratio changes the conversion.
What FOV should I use for competitive FPS games?
For 16:9 monitors, most competitive players use an HFOV between 90 and 110 degrees. Lower FOV makes distant targets appear larger and easier to aim at, while higher FOV gives better peripheral awareness. The sweet spot depends on your play style and game.
Does higher FOV affect performance?
Yes. A higher FOV means the game renders more of the scene, which increases GPU load. The impact varies by game engine, but you may see a small FPS drop at very wide FOV values compared to narrower settings.
What is diagonal FOV?
Diagonal FOV (DFOV) measures the field of view from one corner of the screen to the opposite corner. Some games and VR headsets use diagonal FOV as their primary specification. It is always larger than both HFOV and VFOV for the same view.
Why do some games use VFOV and others use HFOV?
It depends on the game engine. Source-engine games like CS2 use HFOV, while Overwatch and many Unreal Engine titles use VFOV. This matters because setting '90' in a VFOV game produces a very different view than '90' in an HFOV game at the same aspect ratio.

Instantly convert between horizontal, vertical, and diagonal field of view

for any aspect ratio. Enter your HFOV or VFOV value and get all three FOV

measurements in real time with a live visual diagram that scales to your

current angle. Choose from common aspect ratio presets (16:9, 21:9, 4:3,

16:10) or enter a custom ratio. One-click game presets for CS2, Valorant,

Overwatch 2, Apex Legends, and Fortnite let you jump straight to each

title's default FOV. The tool also shows a recommended FOV range based on

your selected aspect ratio so you can dial in the perfect balance between

peripheral awareness and target visibility. All calculations run entirely

in your browser with zero latency — no sign-up required, no data sent to

any server.

Related tools

Mouse Sensitivity Converter

Convert mouse sensitivity between games instantly. Supports CS2, Valorant, Overwatch 2, Apex Legends, and 20+ titles with accurate cm/360 and eDPI calculations.

Crosshair Generator

Design, preview, and export custom crosshairs for CS2, Valorant, and other FPS games. Choose from presets or fine-tune every parameter, then download a transparent PNG or copy console commands.