A camera angle of view is twice the arctangent of the sensor width over twice the focal length. A 50 mm lens on full frame sees about 40 degrees across, and captures a scene about 3.6 metres wide at 5 metres. Enter your focal length, sensor and distance to get the angle and frame size.
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How to Use the Field of View Calculator
- Enter your lens focal length in millimetres.
- Enter the subject distance in metres.
- Choose your sensor size.
- Read the angle of view and the width and height of the scene captured.
| Result | What it means |
|---|---|
| Horizontal angle of view | How wide the lens sees, side to side. |
| Frame width at distance | How much scene fits across the frame at that distance. |
| Frame height at distance | How much scene fits top to bottom. |
| Diagonal angle of view | The corner-to-corner angle, the usual lens spec. |
What Is Field of View?
Field of view, or angle of view, is how much of a scene a lens takes in. A wide lens has a large angle and captures a broad sweep, while a telephoto has a narrow angle and pulls a small slice of the scene up close.
It depends on two things: the focal length of the lens and the size of the sensor behind it. The same lens sees a narrower view on a smaller sensor, which is why crop cameras appear to zoom in. Field of view is what you actually frame in the viewfinder.
How Does the Field of View Calculation Work?
angle of view = 2 x atan(sensor size / (2 x focal length))- Take the sensor width and the focal length.
- The horizontal angle is twice the arctangent of the width over twice the focal length.
- The scene width at a distance is the distance times the sensor width over the focal length.
- Use the sensor diagonal for the diagonal angle of view.
Because the sensor size is in the formula, the angle of view changes with the camera as well as the lens, so a focal length alone does not fix the view.
Field of View Example
A 50 mm lens on a full-frame camera, with its 36 mm wide sensor, has a horizontal angle of view of about 40 degrees. At 5 metres it captures a scene roughly 3.6 metres wide and 2.4 metres tall. Put the same lens on an APS-C body and the narrower sensor cuts the view to about 27 degrees, capturing only around 2.4 metres of width at the same distance.
What Affects the Field of View
Focal Length
A longer lens narrows the angle of view and magnifies the scene; a wider lens opens it up.
Sensor Size
A smaller sensor sees a narrower view for the same lens, the crop effect.
Subject Distance
The angle stays the same, but moving back captures more of the scene across the frame.
Orientation
Turning the camera swaps the wider and narrower angles between horizontal and vertical.
Angles of View Compared
Horizontal angle of view on full frame by focal length.
| Focal length | Angle of view | Type |
|---|---|---|
| 16 mm | About 97 deg | Ultra-wide |
| 35 mm | About 55 deg | Wide |
| 50 mm | About 40 deg | Standard |
| 200 mm | About 10 deg | Telephoto |
A 50 mm lens on full frame is called standard because its angle of view is close to what the human eye perceives as natural.
When to Use a Field of View Calculator
Choosing a Lens
See which focal length frames your subject from where you can stand.
Planning a Shot
Work out how far back to stand to fit a scene in the frame.
Comparing Cameras
Check how a lens angle of view changes between full frame and a crop sensor.
Common Field of View Mistakes
1. Ignoring Sensor Size
A focal length alone does not set the view; the sensor matters just as much.
2. Confusing Focal Length and Angle
Focal length is a lens property; angle of view is what you actually see.
3. Forgetting Orientation
The horizontal and vertical angles differ, so a portrait crop changes the framing.
4. Quoting the Wrong Angle
Makers often list the diagonal angle; the horizontal is usually narrower.
Accuracy and Limitations
The geometry is exact for a rectilinear lens and the sensor width you choose. Wide fisheye and distorting lenses do not follow this simple model.
What it calculates accurately
- Horizontal and diagonal angle of view
- Frame width and height at a distance
- How the view changes with sensor size
What it does not do
- Model fisheye or heavily distorting lenses
- Account for lens breathing at focus
- Include exact sensor aspect ratios for every format
How We Calculate the Result
Frequently Asked Questions
What is field of view in photography?
It is the angle of a scene a lens takes in, set by the focal length and the sensor size. A 50 mm lens on full frame sees about 40 degrees across.
How do you calculate angle of view?
Take twice the arctangent of the sensor size divided by twice the focal length. For a 36 mm sensor and 50 mm lens, that is about 40 degrees horizontally.
How wide is a 50 mm lens?
On full frame a 50 mm lens has a horizontal angle of view of about 40 degrees, considered a standard, natural-looking view.
Does sensor size change field of view?
Yes. A smaller sensor sees a narrower view for the same lens, which is why crop cameras appear to zoom in.
How much scene does my lens capture?
Multiply the distance by the sensor width and divide by the focal length. A 50 mm lens on full frame captures about 3.6 m at 5 m.
What is the difference between horizontal and diagonal angle of view?
Horizontal is side to side; diagonal is corner to corner and is larger. Lens specs usually quote the diagonal angle.
Why does a crop camera look zoomed in?
Its smaller sensor captures a narrower angle of view from the same lens, cropping into the centre of the scene.
Does distance change the angle of view?
No. The angle stays the same, but moving back captures more of the scene across the frame.
Is my data saved?
No. The calculator runs entirely in your browser and nothing you enter is stored or sent anywhere.
Sources
- Angle of view (Wikipedia).
- Image sensor format (Wikipedia).
- Focal length (Wikipedia).
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Explore all hobby calculatorsFor photography planning and educational use. Assumes a rectilinear lens and a 3:2 sensor ratio; fisheye and distorting lenses do not follow this simple geometry. Spotted an error? Let us know.
Author
Shakeel Muzaffar is the Founder and Editor-in-Chief of MultiCalculators.com, bringing over 15 years of experience in digital publishing, product strategy, and online tool development. He leads the platform's editorial vision, ensuring every calculator meets strict standards for accuracy, usability, and real-world value. Shakeel personally oversees content quality, formula verification workflows, and the platform's commitment to publishing tools that are genuinely useful for students, professionals, and everyday users worldwide.
