Actual vs. equivalent focal length
Use the actual focal length for the calculation. A 25mm lens remains 25mm on Micro Four Thirds; its full-frame equivalent is reported after applying crop factor.
Camera Field of View Calculator
Inputs
Results
Enter values to calculate the frame.
| Measure | Angle | Field size |
|---|---|---|
| Horizontal | - | - |
| Vertical | - | - |
| Diagonal | - | - |
| Equivalent full-frame focal length | - |
|---|---|
| Effective sensor diagonal | - |
| Crop factor | - |
| Aspect ratio | - |
| Framing width × height | - |
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Field of view formulas
Angle of view
angle = 2 × arctan(sensor dimension / (2 × focal length))
Use sensor width for horizontal angle, sensor height for vertical angle, and sensor diagonal for diagonal angle.
Field size at distance
field size = 2 × distance × tan(angle / 2)
The same relationship also gives focal length needed to fit a subject: focal length = distance × sensor dimension / subject size.
Variables use the same unit for distance and field size. The model assumes a rectilinear lens focused near infinity; fisheye projection, macro focus, and focus breathing can make real lenses differ.
Worked examples
Choose an example to populate the calculator and show the arithmetic.
How to use this camera FOV calculator
- Select a sensor preset or enter custom dimensions. Full frame, Super 35, 1-inch, action camera, smartphone, 16mm, and medium format presets are included.
- Enter actual focal length, not 35mm equivalent. The calculator reports equivalent full-frame focal length separately.
- Use aspect ratio crop when delivery changes the active frame. A 16:9 or 9:16 crop changes horizontal and vertical angles differently.
- Add distance for real-world coverage. Angle of view stays the same, but frame width and height grow with distance.
- Switch modes for planning. Solve for focal length, camera distance, background field size, or game vertical/horizontal FOV.
Common FOV questions and mistakes
Sensor size changes angle
A smaller active sensor sees a narrower slice of the lens image circle, so the same focal length gives a tighter angle of view.
Horizontal, vertical, and diagonal differ
Horizontal FOV uses frame width, vertical FOV uses frame height, and diagonal FOV uses the corner-to-corner diagonal.
Distance changes field size, not angle
Once focal length and sensor size are fixed, the angle is fixed. Moving farther away simply makes the projected frame wider and taller.
Fisheye and macro results are approximate
Fisheye projection, internal focusing, focus breathing, and macro magnification can break the simple rectilinear near-infinity model.
Game FOV labels vary
Many engines expose vertical FOV, but players often compare horizontal FOV. Always convert with the display aspect ratio.
FAQ
How do I calculate camera FOV?
Use 2 × arctan(sensor dimension / (2 × focal length)). Width gives horizontal FOV, height gives vertical FOV, and diagonal gives diagonal FOV.
What sensor size should I use?
Use the active imaging area for the exact camera mode. Cropped 4K, stabilization, and aspect ratio crops should use the cropped width and height.
Do I enter actual or equivalent focal length?
Enter actual focal length. Equivalent focal length is a comparison value, not the input for this formula.
What does horizontal FOV mean?
Horizontal FOV is the left-to-right angle captured by the frame. It changes when sensor width, focal length, or aspect crop changes.
How do I convert game vertical FOV to horizontal FOV?
Use horizontal = 2 × arctan(tan(vertical / 2) × aspect ratio). The game converter applies that formula for common display ratios.
Is distance required?
No for angle of view. Yes for real-world frame width, frame height, focal length planning, or distance planning.
Why do fisheye lenses differ?
Fisheye lenses use a different projection than rectilinear lenses, so their angle and edge coverage do not follow the same simple formula.
Methodology
Last reviewed
June 23, 2026
June 23, 2026
Assumptions
Rectilinear lens, active sensor crop, focus near infinity.
Rectilinear lens, active sensor crop, focus near infinity.
Test examples
50mm full frame ≈ 39.6° horizontal; 35mm full frame at 3m ≈ 3.09m wide.
50mm full frame ≈ 39.6° horizontal; 35mm full frame at 3m ≈ 3.09m wide.
Formula references
Thin-lens angle-of-view geometry and tangent field-size projection.
Thin-lens angle-of-view geometry and tangent field-size projection.
About this field of view calculator
This calculator translates focal length and active sensor size into clear angles of view. Angle of view is the optical angle captured by the camera; field of view is often used more broadly to mean either that angle or the real-world frame width and height at a given distance. If you supply distance, the tool shows both.
In filmmaking, matching FOV across cameras or between practical and CG shots is critical. The calculator lets you quickly sanity-check that a 25 mm on Super 35 can resemble a longer full-frame lens, or solve the lens needed to fit a 2 m group at 5 m. Photographers can use the distance solver when a location is tight, while VFX and virtual production teams can compare foreground and background coverage.
Because aspect ratio impacts horizontal and vertical angles differently, the tool’s coverage readout is useful when switching between 16:9 and 9:16 deliverables. Knowing the actual width and height at a given distance helps you avoid boom poles or C-stands creeping into frame and ensures set dressing fits within shot boundaries.
Once the page is loaded it works offline, making it handy on set with spotty connectivity. Keep it bookmarked with your focal length charts and use it alongside our depth-of-field calculator to plan sharp, well-framed shots every time.