Mapping & Survey
FOV Calculator
Your camera's field of view and ground coverage at a given altitude.
Planning aid only — not certified flight-planning software or airspace clearance. Always verify results against your own aircraft's manual and check current regulations before flying. Full disclaimer.
Fill in every camera field above to calculate.
The formula
Field of view (FOV) is the angle the camera sees. For a normal (rectilinear) lens it depends only on the sensor size and the real focal length:
FOV = 2 × arctan(sensor dimension ÷ (2 × focal length))
Using the sensor width gives the horizontal FOV, and the sensor height gives the vertical FOV. The ground covered at a given distance follows from the angle:
Coverage = 2 × distance × tan(FOV ÷ 2)
For a camera pointing straight down, the distance is your height above the ground. For an inspection shot, it is your distance from the wall, tower or roof.
Why your spec sheet shows a bigger number
Drone spec sheets usually give one FOV figure, and it is the diagonal angle, corner to corner. The calculator shows the horizontal and vertical angles, which are what you need to work out coverage.
Take the DJI Mavic 3 Pro's main camera: a Four Thirds sensor of about 17.3 × 13 mm with a 12 mm lens (24 mm equivalent).
| Angle | Result |
|---|---|
| Horizontal | 71.6° |
| Vertical | 56.9° |
| Diagonal | 84.1° |
DJI lists the camera's FOV as 84°, which matches the diagonal. The DJI Mini 4 Pro, with a smaller sensor but a matching 24 mm-equivalent lens, gives almost the same angles. Cameras with the same equivalent focal length see the same field of view, whatever their sensor size.
Worked examples
With the Mavic 3 Pro figures above:
- Mapping from 100 m: each photo covers about 144 × 108 m of ground.
- Inspecting a facade from 20 m away: the frame is about 29 m wide.
- Fitting a 50 m wide building in the frame, camera pointing down: you need to be about 35 m above the roof, plus some margin, since subjects at the edge of the frame are harder to use.
The last calculation is the formula turned around: distance = width ÷ (2 × tan(horizontal FOV ÷ 2)).
Photo vs video
The calculator assumes you use the whole sensor, which is true for most photos in the camera's native aspect ratio (usually 4:3 on drones). Video is different:
- 16:9 video crops the top and bottom of a 4:3 sensor. On the cameras above, the vertical FOV drops from about 57° to about 44°.
- Some video modes crop further, for example high frame rates or digital zoom. Both angles then shrink.
If you plan inspection video, check your camera's manual for the crop in the mode you'll use, and reduce the coverage accordingly.
Where to find the right inputs
- Focal length: use the real focal length, not the 35 mm-equivalent. It is in the photo's EXIF data; our EXIF Viewer shows it.
- Sensor size: spec sheets often list only a format such as "1-inch" or "1/1.3-inch". These are traditional names, not measurements; a "1-inch" sensor is about 13.2 × 8.8 mm. The calculator's drone presets fill in both values for common models.
From FOV to mapping plans
FOV sets the size of each image on the ground. The number of pixels across that footprint sets the level of detail, the ground sample distance. Use the GSD Calculator for resolution, then the Overlap Calculator to space your photos and flight lines. Our guide to ground sample distance explains how the pieces fit together.