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FOV calculator

Lock any 2 of screen size, viewing distance, or FOV — the others are computed automatically.

Free & unlimitedWorks offline

Lock the values you know (2 of 4 locked)

Game FOV (HFOV) (°)
Viewing FOV (HFOV) (°)
Screen size (in)
Viewing distance (cm)
Aspect ratio
Viewing angle
EyeMonitor49.4°65 cm
Horizontal FOV
49.4°
Vertical FOV
29.0°
Diagonal FOV
55.6°
Screen width
59.8 cm
Game-specific FOV values
GameDefault HFOVDefault VFOVNote
CS2 / Valorant106.26°73.74°Fixed 106 HFOV at 16:9, varies with aspect ratio
Apex Legends110°70°Slider 70-110, default 70 (70 is vFOV)
Overwatch 2103°71°Slider 80-103 HFOV
Fortnite80°59°Default 80 HFOV (slider available)
Battlefield 204295°65°Default 74-105 vFOV
Call of Duty120°80°80-120 FOV slider
Escape from Tarkov75°59°50-75 vFOV
Rainbow Six Siege90°59°60-90 FOV slider

FOV uses HFOV = 2 · atan(W / 2D) where W is screen width and D is viewing distance. VFOV = 2 · atan(tan(HFOV/2) / aspect). This gives your physical field of view, which may differ from in-game FOV settings.

All processing happens in your browser. No data is sent to any server.

Field of view is a property of your desk before it is a setting in a game: a screen of a given width at a given distance covers one specific angle of your vision, and every FOV argument is really an argument about that angle. This calculator solves the relationship in any direction. Lock the two values you know — screen size and viewing distance, say, or a FOV you already run and the distance you sit at — and it computes the rest, then breaks the answer out into horizontal, vertical and diagonal degrees so you can carry it into whichever game you are configuring. A drawn diagram shows the cone your screen actually occupies, and a reference table lists the default and adjustable ranges for eight popular shooters. For sim racing, where each title uses a different axis and a different menu, the per-game pages linked below give the exact value and menu path instead.

Key facts about FOV calculator

Key facts about FOV calculator
What it solvesFour related quantities — game FOV, viewing FOV, screen size and viewing distance — of which any two locked ones determine the rest.
Core equationhFOV = 2 x atan(W / 2D), where W is the visible width of the screen and D is the distance from your eye to it.
Vertical conversionvFOV = 2 x atan(tan(hFOV / 2) / aspect), which is why the vertical figure is always the smaller on a landscape screen.
Aspect ratios offered16:9, 16:10, 21:9, 32:9, 4:3 and 3:2 on the lock-based solver.
UnitsScreen size in diagonal inches, viewing distance in centimetres, every angle in degrees.
Worked exampleA 27-inch 16:9 panel at 65 cm covers 49.4 degrees horizontally, 29.0 vertically and 55.6 diagonally.
DiagramAn inline SVG draws the cone from your eye to the screen with the horizontal angle and the distance labelled — no canvas, no image file.
Reference tableDefault horizontal and vertical values plus the adjustable range for CS2 and Valorant, Apex Legends, Overwatch 2, Fortnite, Battlefield 2042, Call of Duty, Escape from Tarkov and Rainbow Six Siege.
Lock ruleExactly two inputs stay locked at a time; unlocking a third is refused with a message rather than silently producing an unsolvable set.
Game FOV and viewing FOVThe solver treats both as horizontal degrees, so locking one sets the other. Games that take vertical degrees need the vertical figure from the results row instead.
Not covered herePer-game menu paths, unit quirks and range clamps — those live on the sim-racing pages, because there is no single answer that is true of every title.

What happens to your file

Nothing is uploaded, because nothing is uploaded-shaped: the only inputs are four numbers and an aspect ratio. Every result comes from JavaScript arithmetic running in this tab, the diagram is an inline SVG drawn from those same numbers, and the reference table is a static array shipped with the page. There is no request to any server, no storage, and no analytics on what you type. Close the tab and the numbers are gone.

About this tool

  1. 1

    Decide what you know

    The usual case is screen size and viewing distance, which are locked by default. If you instead know the FOV you want and the screen you have, lock those two and let the distance be computed.

  2. 2

    Lock exactly two

    Use the padlock beside each field. Locking a third is refused, because the geometry is fully determined by two of the four values plus the aspect ratio.

  3. 3

    Pick the aspect ratio

    This changes the vertical and diagonal results substantially. A 21:9 panel of the same diagonal is wider and shorter than a 16:9 one, so its vertical angle is smaller.

  4. 4

    Read the three angles

    The results row gives horizontal, vertical and diagonal degrees. Which one you need depends on the game — most shooters take horizontal, several racing sims take vertical.

  5. 5

    Check the diagram

    The cone shows the angle your screen physically occupies at the distance you entered. If it looks implausibly wide, the distance is probably wrong.

  6. 6

    Use the reference table

    The table lists defaults and adjustable ranges for eight popular titles, which is enough to see whether the value you need is even reachable in that game's menu.

Specs & compatibility
InputsGame FOV in degrees, viewing FOV in degrees, screen size in diagonal inches (1 to 200), viewing distance in centimetres (1 to 500), and an aspect ratio.
OutputsHorizontal, vertical and diagonal FOV to one decimal, plus the visible screen width in centimetres.
Solver requirementTwo of the four values must be locked. With fewer, the page says so rather than showing a guess.
Angle limitsFOV fields accept 1 to 179 degrees; the geometry breaks down at 180, where the screen would have to be infinitely wide.
Browser supportAny browser with JavaScript. No canvas, no WebAssembly, no permissions requested.
OfflineWorks with no network once the page has loaded.
Account or installNone — no signup, no extension, nothing to download.
  • Measure eye to screen rather than desk to screen. The difference is often 10 cm, which is worth three or four degrees.
  • A wider FOV than your geometry supports draws the world smaller than life, which reads as the game feeling slow; a narrower one exaggerates speed and hides the periphery.
  • Horizontal and vertical degrees are not interchangeable. On a 16:9 screen the horizontal figure is roughly twenty degrees larger at typical desk distances.
  • Ultrawide monitors buy width, not scale: at the same distance the vertical angle is unchanged, so a vertical-FOV game will want the same number it wanted before.
  • If a game clamps the value you need, the fix is physical — move closer, or use a larger screen — not a compromise value.
  • For sim racing, use the per-game pages below instead: each title uses a different axis and menu path, and getting that wrong costs more than any rounding here.
  • Working out the angle your monitor actually covers before arguing about what FOV to run.
  • Converting a horizontal FOV from one game into the vertical figure another game expects.
  • Finding the viewing distance at which a given screen would produce a FOV you already like.
  • Checking whether an ultrawide upgrade changes the vertical angle at all, which it does not at the same distance.
  • Comparing the default and adjustable FOV ranges of eight shooters in one table before deciding which to change.
It depends entirely on the title, and the two families are far apart. Most first-person shooters, plus iRacing and Automobilista 2, take the horizontal angle. Assetto Corsa, Assetto Corsa Competizione, rFactor 2, Le Mans Ultimate and BeamNG.drive take the vertical one. On a 27-inch 16:9 screen at 60 cm those are 53 and 31 respectively for the same rig — swap them and the world is drawn at roughly half or double life size. This page gives you all three angles; the per-game pages tell you which one to type and where.
Because the geometry is a single equation linking field of view, screen width and viewing distance, with the aspect ratio turning the screen's diagonal into a width. Fix any two of those and the third follows; fix only one and there are infinitely many answers. The calculator refuses to lock a third rather than quietly ignoring one of your inputs, so what you see on screen is always a solution to exactly what you asked.
Viewing FOV is the angle your screen physically occupies from where you sit — a fact about your desk. Game FOV is the angle the engine renders into that screen — a setting. They should match, and this solver treats them as the same horizontal value so that locking one sets the other. When they differ, the ratio between them is exactly how far from life size the world is being drawn, which is the whole reason a mismatched FOV makes a game feel slow or nauseating.
It changes the measurement, not the maths. A curved panel's visible image is longer than the straight line between its edges and it wraps slightly toward you at the sides, so the effective width is larger than a flat screen of the same quoted diagonal. Run a tape along the curve of the picture and work from that width. The difference on a 1000R 34-inch panel is a couple of degrees — real, but smaller than the error most people make guessing their seating distance.
Because the screen is wider than it is tall, and field of view is an angle rather than a length. On a 16:9 panel the picture is 1.78 times wider than it is high, and the conversion runs through tangents rather than a straight ratio: vFOV = 2 x atan(tan(hFOV / 2) / 1.78). At 53 degrees horizontal that gives 31 vertical. The gap widens on an ultrawide and narrows on a 4:3 screen, which is why aspect ratio has to be part of any honest FOV calculation.
Only if you want the world drawn smaller than life. A wide FOV squeezes more of the scene into the same glass, so every object covers fewer pixels and moves less across the screen per metre you travel — you see more, at the cost of scale, distance judgement and apparent speed. In a shooter that trade is often worth it, because spotting a flank matters more than judging a closing speed. In a racing sim it usually is not, which is why sim racers calculate the value instead of maximising it.

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