A focal length on its own does not say how much a lens sees. The same 50 mm lens takes in a wide view on a full-frame camera and a much narrower one on a smaller sensor, which is why lens talk keeps turning into crop factors and 35 mm equivalents. This field of view calculator works out all three from the two numbers that decide them.
Put in the focal length printed on the lens and pick your camera's sensor, or type in its size. It works out the angle of view across, down and corner to corner, the crop factor, the 35 mm-equivalent focal length by CIPA's own rule, and how wide a scene the lens takes in at the distance you give. Every sensor size is the camera maker's published figure, and the list of what it cannot tell you is below the answer.
In this guide
The field of view calculator
The focal length printed on the lens, not a 35 mm-equivalent figure. For a zoom, the setting you will shoot at.
The sensor size is in the camera's specifications. Pick Other and type it in if yours is not listed.
Only used when the sensor is set to Other: the width from the camera's specifications.
Only used when the sensor is set to Other: the height from the same specifications.
How far away the thing you are photographing is, for the width and height of the scene.
How that is worked out, line by line
- Sensor width36.0 mm
- Sensor height24.0 mm
- Sensor diagonal43.27 mm
- Angle of view down27.0 degrees
- Crop factor1.00 x
- Width of the scene at your distance7.20 m
- Height of the scene at your distance4.80 m
On those numbers you are in the Over 35 and up to 70 mm equivalent band, which is the section below.
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Where every number here comes from
No part of this was measured on a bench here. This site works from published specifications and from what owners report, and every number below is either one you typed in or a published figure with its source named next to it.
The figures this page supplies
- Width of the 35 mm frame: 36 mm. CIPA DCG-001 takes the 35 mm camera's image area as the reference for an equivalent focal length; that frame is 36 by 24 mm, whose diagonal is the 43.27 mm the guideline names. Full-frame sensors are made to it: Nikon gives the Z5II's as 35.9 by 23.9 mm.
- Height of the 35 mm frame: 24 mm. The 24 of the same 36 by 24 mm frame.
- Width of a Nikon DX sensor: 23.5000 mm. Nikon's online manual for the Z50II, Specifications: a 23.5 x 15.7 mm CMOS sensor (Nikon DX format).
- Height of a Nikon DX sensor: 15.7000 mm. The 15.7 of the same Nikon figure.
- Width of a Canon APS-C sensor: 22.3000 mm. Canon's published EOS R10 specifications: image sensor approx. 22.3 x 14.9 mm.
- Height of a Canon APS-C sensor: 14.9000 mm. The 14.9 of the same Canon figure.
- Width of a Micro Four Thirds sensor: 17.3000 mm. Panasonic's published LUMIX G9II specifications: Live MOS sensor, 17.3 x 13.0 mm.
- Height of a Micro Four Thirds sensor: 13 mm. The 13.0 of the same Panasonic figure.
- Width of a 1-inch type sensor: 13.2000 mm. Sony's published RX100 VII specifications: 1.0-type (13.2 mm x 8.8 mm) Exmor RS CMOS sensor.
- Height of a 1-inch type sensor: 8.8000 mm. The 8.8 of the same Sony figure.
Why each step is the step it is
- Sensor width:
ff_w * is_1 + dx_w * is_2 + cn_w * is_3 + mft_w * is_4 + one_w * is_5 + custom_w * is_6. The maker's published width for the sensor picked, or the width you typed for Other. - Sensor height:
ff_h * is_1 + dx_h * is_2 + cn_h * is_3 + mft_h * is_4 + one_h * is_5 + custom_h * is_6. The published height for the same sensor, or the height you typed. - Sensor diagonal:
Math.sqrt(sens_w * sens_w + sens_h * sens_h). Pythagoras on the sensor's width and height. - Angle of view across:
2 * Math.atan(sens_w / (2 * focal_mm)) * 180 / Math.PI. A rectilinear lens focused at infinity sits one focal length in front of the sensor, so half the sensor's width over the focal length is the tangent of half the angle: 2 x atan(width / 2f). - Angle of view down:
2 * Math.atan(sens_h / (2 * focal_mm)) * 180 / Math.PI. The same relation on the sensor's height. - Angle of view corner to corner:
2 * Math.atan(sens_d / (2 * focal_mm)) * 180 / Math.PI. The same relation on the sensor's diagonal. This is the angle lens makers usually print in a lens's specifications. - Crop factor:
ff_d / sens_d. The 35 mm frame's diagonal over your sensor's, the ratio CIPA DCG-001 multiplies the focal length by. - 35 mm-equivalent focal length:
focal_mm * crop. CIPA DCG-001: the focal length times 43.27 mm over the sensor's diagonal. A full-frame lens of this focal length gives the same angle corner to corner. - Width of the scene at your distance:
dist_m * sens_w / focal_mm. Similar triangles: the scene's width is to your distance as the sensor's width is to the focal length. It holds when the subject is far away compared with the focal length. - Height of the scene at your distance:
dist_m * sens_h / focal_mm. The same triangles on the sensor's height.
What this cannot tell you
Every calculator has an edge, and a page that hides its edge is worse than no page at all. Here is this one's.
- It is geometry on published figures. No lens was mounted or photographed for it, and this site has not had these cameras in its hands.
- It assumes a rectilinear lens focused at infinity. A fisheye lens follows a different projection, and many lenses take in a narrower angle when focused close, so close-up and macro work sees less than this says.
- Distortion, and the in-camera correction most cameras apply to it, changes a wide lens's real angle a little. The maker's published angle of view for that lens is the figure to trust where the two differ.
- Sensor sizes differ by a fraction of a millimetre between cameras of the same format, and some cameras crop the sensor for video or for stabilisation. Pick Other and type in your own camera's figures when it matters.
- The 35 mm-equivalent figure matches the angle of view only. Depth of field and background blur also depend on the aperture and the distance, and this calculator does not work those out.
What that equivalent focal length is for
These follow from the answer above and nothing else. Each heading below covers one span of results, so read the one the calculator pointed you at and ignore the rest.
35 mm equivalent or wider
A wide view: on full frame a 35 mm lens takes in about 63 degrees corner to corner, and shorter lenses more. This is the range for rooms, landscapes, groups and travel shots where the setting matters as much as the subject. Most phone main cameras are described by their equivalent focal length, so this figure compares directly with theirs; the guides below cover cameras for that kind of trip.
Good Inexpensive Camera for Vacation Pictures: Best of 2026 covers this range in full.
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Over 35 and up to 70 mm equivalent
Between a moderate wide angle and a short telephoto, around the 43 mm diagonal of the 35 mm frame itself, which is the focal length photographers call normal. This is the everyday range for street, family and general photography. The guides below compare cameras whose kit lenses cover it.
Best Camera for Photography (2026): 3 Picks Worth Buying covers this range in full.
Digital Photography Review 2026: Nikon Z5II Worth It? covers this range in full.
Longer than 70 mm equivalent
A telephoto view: at 70 mm equivalent the angle corner to corner is about 34 degrees, and it keeps narrowing past that, which brings distant subjects closer and flattens the space between things. It suits portraits, sport and wildlife. A smaller sensor gives the same lens a longer equivalent focal length, so it reaches further; the guides below cover the cameras.
Best Camera for Photography (2026): 3 Picks Worth Buying covers this range in full.
Digital Photography Review 2026: Nikon Z5II Worth It? covers this range in full.
Sensors come in different shapes as well as sizes: full frame and APS-C are 3:2, Micro Four Thirds is 4:3, and the aspect ratio calculator works out width and height for any ratio. A field of view calculator can only be as right as the focal length and sensor size you give it, so take both from the specifications of the lens and the camera you will use.
Questions about the field of view calculator
How do you calculate field of view from focal length?
Divide the sensor's width by twice the focal length, take the arctangent, and double it. A 50 mm lens on a full-frame sensor 36 mm wide takes in 39.6 degrees across, 27 degrees down and 46.8 degrees corner to corner. The same lens on a Micro Four Thirds sensor 17.3 mm wide takes in 19.6 degrees across. This field of view calculator does that sum for any focal length and sensor, for a lens focused at infinity.
What is a 35 mm-equivalent focal length?
The focal length that gives the same angle of view on a full-frame camera. CIPA's guideline works it out as the focal length times 43.27 mm, the 35 mm frame's diagonal, over the sensor's diagonal. A 35 mm lens on a Nikon DX sensor (28.26 mm across the diagonal) has a crop factor of 1.53 and is equivalent to 54 mm. A 25 mm lens on Micro Four Thirds is equivalent to 50 mm.
Does a crop sensor change the field of view?
Yes. The lens projects the same image, and a smaller sensor records less of it, so the angle narrows. A 50 mm lens takes in 46.8 degrees corner to corner on full frame, 30 degrees on a Canon APS-C sensor and 18 degrees on a 1-inch type sensor. The focal length itself does not change; only how much of the picture the sensor keeps, which is what the crop factor measures.
How wide an area does a lens take in at a given distance?
The distance times the sensor's width over the focal length. A 50 mm lens on full frame takes in a scene 7.2 m wide and 4.8 m tall from 10 m away. A 24 mm lens from the same spot takes in 15 m by 10 m, and a 200 mm lens 1.8 m by 1.2 m. It holds while the subject is far away compared with the focal length, which is most photographs except close-ups.
Why does a lens maker's angle of view differ from the calculator?
Usually because it is the corner-to-corner angle, which is the one lens specifications tend to print: 46.8 degrees for a 50 mm lens on full frame, against 39.6 degrees across. A small difference beyond that comes from distortion and the camera's correction of it, from focusing closer than infinity, or from a focal length rounded on the lens barrel. Where the two disagree, the maker's own figure for that lens is the one to trust.
Sources
- CIPA DCG-001: guidelines for noting digital camera specifications (number of pixels, image file and focal length of the lens): Defines the 35 mm-equivalent focal length as the focal length times 43.27 mm, the 35 mm frame's diagonal, over the diagonal of the camera's image area.
- Edmund Optics: understanding focal length and field of view: Gives the angular field of view as 2 x atan of the sensor dimension over twice the focal length, and warns that distortion in short focal length lenses changes it.
- Nikon Z5II online manual: specifications: A full-frame sensor of 35.9 by 23.9 mm, within a fraction of a millimetre of the 36 by 24 mm frame.
- Nikon Z50II online manual: specifications: The 23.5 by 15.7 mm Nikon DX sensor.
- Canon EOS R10 specifications: Canon's APS-C sensor at approximately 22.3 by 14.9 mm.
- Panasonic LUMIX G9II specifications: A Micro Four Thirds sensor of 17.3 by 13.0 mm.
- Sony RX100 VII specifications: A 1.0-type sensor of 13.2 by 8.8 mm.
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