Field of View Calculator
The actual optical focal length of your lens (from the lens barrel or EXIF data)
Distance from camera to subject for linear FOV calculation
Enter Lens & Sensor Details
Enter your focal length, sensor format, and subject distance above to see angles of view and scene coverage.
How to Use This Calculator
Select Your Calculation Mode
Choose 'Calculate FOV' to find out how much a lens covers, 'Find Focal Length' to determine which lens you need for a specific scene width, or 'Find Distance' to find out how far to stand for a desired frame size.
Enter Focal Length and Sensor Format
Type your lens focal length in millimetres — use the value printed on your lens barrel or found in EXIF data. Select your camera sensor format from the dropdown (e.g. Full Frame, APS-C Nikon, Micro Four Thirds) or choose Custom and enter exact sensor dimensions.
Set Subject Distance and Units
Enter the distance from your camera to the subject or scene. Toggle between metres and feet to match your preferred unit system. The linear scene coverage (scene width, height, and diagonal) will be calculated for this distance.
Read Your Results
Review the horizontal, vertical, and diagonal angles of view — these are fixed properties of the lens-sensor pair. Below them, see the actual scene dimensions at your entered distance. The sensor details panel shows crop factor, 35mm-equivalent focal length, and aspect ratio.
Frequently Asked Questions
What is the difference between angle of view and field of view?
Angle of view (AOV) is a fixed property of the lens and sensor combination, measured in degrees. It describes the cone of vision the camera captures and does not change with distance — a 50mm full-frame lens always has a 39.6° horizontal angle of view. Field of view (FOV) refers to the actual physical dimensions of the scene captured at a specific distance. Move further from your subject and the field of view widens in physical terms (more scene fits in the frame) while the angle of view stays constant. This calculator computes both: angles under 'Angles of View' and physical dimensions under 'Scene Coverage at Distance'.
What is crop factor and why does it matter?
Crop factor (also called focal length multiplier) is the ratio of the 35mm full-frame sensor diagonal (43.27mm) to your sensor's diagonal. A full-frame sensor has a crop factor of 1.0x. An APS-C Nikon sensor with a 28.2mm diagonal has a crop factor of about 1.53x. This means a 50mm lens on an APS-C body frames the same scene as a 76mm lens on full frame (50 × 1.53 = 76.5). Smaller sensors effectively 'crop into' the image, giving a narrower field of view with the same lens. This is useful for telephoto reach but limits wide-angle coverage.
How do I use the reverse solver to choose the right focal length?
Switch to 'Find Focal Length' mode. Enter the desired scene width — for example, 3 metres to capture a standard doorway width — and the distance from which you plan to shoot, say 4 metres. Select your sensor format. The calculator uses the formula focal_length = (distance × sensor_width) / desired_FOV_width to give you the required focal length. If the result is 28mm, use a 28mm or wider lens. If the result is between standard focal lengths (e.g. 37mm), choose the closest available focal length and recalculate to see how the actual coverage compares.
Does this calculator work for zoom lenses?
Yes — enter the specific focal length you are zoomed to, not the zoom range. For example, if you have a 24-70mm lens set to 35mm, enter 35 in the focal length field. Modern DSLR and mirrorless cameras record the actual focal length used in the EXIF data of each image, which is the most accurate source. For video work where you might be at an unmarked zoom position, use the closest zoom ring marking or consult the manufacturer's focal length chart for your specific lens model.
Why is the calculated FOV different from what I see in camera?
Several factors can cause differences. First, zoom lenses often have slightly inaccurate focal length markings — the actual focal length may differ by 5–10% from the label. Second, the sensor area active during capture may be smaller than the full sensor if your camera is shooting in a crop mode (common in video on some cameras). Third, extreme close-focus distances cause focus breathing in some lenses. Fourth, fisheye and other special projection lenses do not follow the rectilinear formula used here. For best accuracy, use EXIF focal length data and verify you are shooting in your camera's full sensor mode.
What focal length gives a natural, undistorted perspective?
The 'normal' or 'standard' focal length for a sensor is approximately equal to the sensor's diagonal. For full-frame (43.27mm diagonal), a 43–50mm lens is considered standard and produces perspective similar to natural human vision. On APS-C (28–29mm diagonal), a 28–35mm lens is standard. On Micro Four Thirds (21.6mm diagonal), a 20–25mm lens gives a natural perspective. Going shorter than standard (wide angle) exaggerates depth and enlarges foreground elements. Going longer (telephoto) compresses depth and makes background elements appear larger relative to the subject.