Does a higher FOV lower FPS?

Slightly. A wider view puts more geometry on screen, so the CPU and GPU have more to draw — usually a few percent, not a large hit.

Why does my FOV shrink on an ultrawide?

Many engines lock vertical FOV. Widening the screen then adds picture at the sides; games that lock horizontal FOV instead cut the top and bottom.

Home › Calculators › FOV Converter

Convert field of view between horizontal, vertical and diagonal, and across aspect ratios and games.

Does a higher FOV lower FPS?: Slightly. A wider view puts more geometry on screen, so the CPU and GPU have more to draw — usually a few percent, not a large hit.
Why does my FOV shrink on an ultrawide?: Many engines lock vertical FOV. Widening the screen then adds picture at the sides; games that lock horizontal FOV instead cut the top and bottom.