Camera Field of View Calculator
Whether you are planning a photoshoot or just a photography enthusiast, our camera field of view calculator will help you learn the whole picture. With this tool you can calculate the field of view of any camera — and there is more to it than a single number.
Keep reading to discover:
- What is the field of view of a camera?
- What is the difference between the angle of view and the field of view?
- How to calculate the angle of view.
- How to determine the field of view of a camera.
- Some focused examples. 📸
What is a camera field of view?
📷 Cameras are our way to create memories — instants preserved forever — from what we can see. However, their electronic eyes have some limitations when it comes to how much of those memories they record. It pays to think beforehand about what you want to include in your pictures, and many photographers find it helpful to know their camera's field of view.
The concept is not unique to photography: astronomers use exactly the same idea, just with eyepieces instead of sensors.
⚠️ There is quite a bit of confusion online on this matter, with various definitions and interpretations. Here we give the one that makes the most sense to us — and we show both quantities side by side so you can use whichever your workflow needs.
The basic concept underlying the entire matter is that a camera captures a single, defined portion of the real world at once. How large that portion is depends on the camera set-up — particularly on the lens and the sensor behind it.
Imagine drawing a rectangle in front of you. How would you tell someone how big it is? You have two ways of saying so:
- Using angles, which specifies the dimensions in absolute terms; or
- Using a pair of length measurements — you can't say only "1 meter", you have to say "1 meter at 4 meters of distance". This is a relative measurement.
The two concepts are used almost interchangeably because they describe the same thing. Their definitions, however, are different. Let's look at them in detail.
The angle of view
When we use angles to define the dimensions of a picture, we talk of the angle of view (AOV). It is easy to visualize: your camera lies at the center of a sphere, and connecting the corners of the scene you are capturing to that center gives you a set of three angles:
- A horizontal angle;
- A vertical angle; and
- A diagonal angle.
The first two define the width and the height of the rectangle corresponding to our sensor. Notice that these quantities are absolute: you can place the "sphere" as far away as you like — even at an infinite distance — and the angle of view will still be the same.
How to calculate the angle of view of a camera
The angle of view depends on only two things: the size of the sensor and the focal length of the lens.
AOV = 2 × arctan(sensor size ÷ 2f)
Use the sensor width for the horizontal angle, the sensor height for the vertical angle, and the sensor diagonal for the diagonal angle of view. The diagonal figure is the one lens manufacturers usually print on the box.
💡 Strictly speaking this formula assumes the lens is focused at infinity. When you focus close, the lens moves away from the sensor and the true angle narrows slightly to 2 × arctan(sensor size ÷ 2f(1 + m)), where m is the magnification. Our calculator shows this corrected angle whenever it makes a visible difference.
The field of view
The field of view (FOV) is the same rectangle, but measured in real-world units — meters, feet, inches — at a given distance from the camera. It is a relative measurement: it is meaningless without stating how far away the subject is. Double the distance and you double the field of view.
This is the number you want when you are asking practical questions: will the whole group fit in the frame from where I'm standing? How much of the wall will this security camera see?
How to calculate the camera field of view
Since the angle of view already describes the shape of the cone the camera sees, the field of view at a distance u follows from simple trigonometry:
FOV ≈ 2 × u × tan(AOV ÷ 2)
That approximation is excellent for ordinary distances. Our calculator goes one step further and uses the exact thin-lens result, which also accounts for the lens being racked forward to focus:
FOV = sensor size × (u − f) ÷ f
The two agree closely as long as the subject is far away compared with the focal length, and they diverge noticeably for close-up and macro work — which is exactly when photographers get surprised by how little of the scene actually fits.
A quick summary: angle of view vs. field of view
| Angle of view | Field of view | |
|---|---|---|
| Measured in | Degrees | Feet, meters, inches, cm |
| Depends on distance? | No — absolute | Yes — relative |
| Depends on the lens? | Yes | Yes |
| Depends on the sensor? | Yes | Yes |
| Answers | "How wide is this lens?" | "Will they all fit from here?" |
...and some examples!
A 50 mm "normal" lens on full frame. The angles of view are 39.6° horizontally, 27.0° vertically and 46.8° diagonally. Stand 15 ft (4.6 m) from your subject and the frame covers about 10.7 ft × 7.1 ft (3.26 m × 2.17 m) — comfortable for a small group.
A 24 mm wide-angle on full frame. The diagonal angle of view opens up to 84.1°, and from the same 15 ft you now cover roughly 22.4 ft × 14.9 ft (6.82 m × 4.55 m). That's an entire room.
A 200 mm telephoto on full frame. The diagonal angle collapses to 12.3°, and from 15 ft the frame is only about 2.6 ft × 1.7 ft (0.79 m × 0.52 m) — a head-and-shoulders portrait.
Does the sensor size of a DSLR matter?
Very much so. The focal length is a property of the lens alone, but the angle of view is a property of the lens plus sensor. Mount that same 50 mm lens on an APS-C body (23.6 × 15.7 mm) and the diagonal angle of view drops from 46.8° to about 31.7°: the smaller sensor simply crops into the image circle the lens projects.
From 15 ft, the full-frame camera covers 10.7 ft of width, while the APS-C camera covers only 7.0 ft. That ratio — 1.53× — is the crop factor, and it is why a 50 mm lens on APS-C is described as "75 mm equivalent". Our calculator reports the crop factor and the 35 mm-equivalent focal length for every sensor, and it lists what your lens would do on ten different sensor formats side by side.
Frequently Asked Questions
What is the difference between the angle of view and the field of view?
The angle of view is measured in degrees and does not depend on distance. The field of view is measured in length units and describes how much of the world fits in the frame at a specific distance. One is the cone; the other is a slice through it.
How do I calculate the field of view of a camera?
Take the sensor dimension, multiply it by the subject distance minus the focal length, and divide by the focal length: FOV = sensor × (u − f) ÷ f. For everyday distances the simpler FOV = 2 × u × tan(AOV ÷ 2) gives practically the same answer.
Does zooming change the field of view?
Yes. Zooming in increases the focal length, which narrows both the angle of view and the field of view. Zooming from 24 mm to 200 mm on full frame shrinks the diagonal angle from 84° to 12° — a factor of seven in linear coverage.
Why does my phone see so much more than my camera?
Phone sensors are tiny (about 6.2 × 4.6 mm for a 1/2.3-inch sensor), so phone makers fit very short lenses — often 4–7 mm. That short focal length combined with a small sensor still yields a wide angle of view, which is why phones are so good at fitting a whole room into one shot.
Does the field of view change when I shoot in portrait orientation?
The sensor doesn't change, but which edge is horizontal does. Rotating the camera swaps the horizontal and vertical angles of view; the diagonal angle stays exactly the same. Use the orientation selector above to see both.
How close can I focus before the formulas break down?
They don't break down — but the simple infinity approximation does. Once the subject is closer than about ten focal lengths, the exact thin-lens field of view is measurably smaller than the approximation, and at 1:1 macro magnification the frame covers exactly the size of the sensor itself.