🖥️ Field of View Calculator

FOV Converter

Q: Why does FOV change when I switch aspect ratios?

Most modern engines use "Hor+" scaling: your vertical FOV stays fixed and the horizontal FOV expands or shrinks with your screen's aspect ratio. Moving from 16:9 to an ultrawide 21:9 monitor at the same horizontal FOV setting would show noticeably less on the sides than intended, so the value needs to be converted to keep the same field of view feel.

Q: Is this formula accurate for every game?

This calculator uses the standard Hor+ scaling formula, which covers most modern engines (Source, Unreal, Frostbite, id Tech). A minority of older titles use Vert- or fixed-FOV scaling instead, where the conversion works differently — check your specific game's FOV behavior if the converted value looks off in-game.

Convert your horizontal field of view between aspect ratios so your monitor upgrade doesn't change how much you can see.

Origem (From)

Horizontal FOV atual

Aspect Ratio Atual

Destino (To)

Aspect Ratio Alvo

Horizontal FOV Convertido

105.4°

Vertical FOV (constante)

58.7°

Diferença

+15.4°

Método

Hor+ Scaling

What Is Hor+ FOV Scaling?

Most modern game engines use Hor+ (horizontal plus) scaling: your vertical field of view is fixed, and the horizontal field of view expands or contracts based on your screen's aspect ratio. That means the same numeric FOV setting looks and feels different on a 16:9 monitor than on an ultrawide 21:9 or 32:9 one.

This tool converts your horizontal FOV between aspect ratios while keeping the vertical FOV constant, using the formula: newFOV = 2 × atan(tan(oldFOV / 2) × (newRatio / oldRatio)).

Frequently Asked Questions

Why does FOV change when I switch aspect ratios?

With Hor+ scaling, keeping the same horizontal FOV number after switching to a wider monitor would actually show less on the sides relative to what you had before — the value needs to be converted upward to preserve the same peripheral vision.

Is this formula accurate for every game?

It covers most modern engines (Source, Unreal, Frostbite, id Tech). A minority of older titles use Vert- or fixed-FOV scaling instead, where the conversion works differently.