Photography Tool

Crop Factor Calculator

Work it out either way: what your lens looks like on your sensor, or which lens to buy to match a full-frame look. Full-frame, APS-C, Micro Four Thirds, medium format and more.

Common cameras and their crop factors

Every figure below is computed the same way the calculator does it — full-frame diagonal (43.27mm) divided by the sensor's own diagonal — so the table and the tool always agree.

Sensor format	Crop factor	Example bodies
Medium Format43.8×32.9mm	0.79×	Fujifilm GFX100 II, Fujifilm GFX100S II, Hasselblad X2D 100C
Full Frame36×24mm	1.00×	Sony α7 IV / α7R V / α1 II, Canon EOS R5 Mark II / R6 Mark II / R1, Nikon Z6 III / Z8 / Z9, Panasonic Lumix S5 II
APS-H27.9×18.6mm	1.29×	Canon EOS-1D Mark IV, Leica M8
APS-C23.5×15.6mm	1.53×	Fujifilm X-T5 / X-H2S / X100VI, Sony α6700 / ZV-E10 II / FX30, Nikon Z50 II / Zfc / Z30
APS-C (Canon)22.3×14.9mm	1.61×	Canon EOS R7, Canon EOS R10, Canon EOS R50
Micro Four Thirds17.3×13mm	2.00×	OM System OM-1 Mark II, Panasonic Lumix GH7, OM System OM-5
1-inch13.2×8.8mm	2.73×	Sony RX100 VII, Canon PowerShot G7 X Mark III
2/3"8.8×6.6mm	3.93×	Fujifilm X10 / X20 / X30
1/1.7"7.44×5.58mm	4.65×	Canon PowerShot G12 / G15 / G16, Pentax Q7
1/2.3"6.17×4.55mm	5.64×	Nikon Coolpix P1000, Canon PowerShot SX740 HS

By brand

Canon
Full-frame: 1.00× · APS-C: 1.61× · APS-H: 1.29× (older pro bodies)
Nikon
Full-frame (FX): 1.00× · APS-C (DX): 1.53×
Sony
Full-frame: 1.00× · APS-C: 1.53× · 1-inch (RX100): 2.73×
Fujifilm
Medium format (GFX): 0.79× · APS-C (X-mount): 1.53×
OM System / Panasonic
Micro Four Thirds: 2.00× · Panasonic full-frame (S): 1.00×
Pentax / Ricoh
Full-frame (K-1): 1.00× · APS-C (K-3): 1.53×

How crop factor actually works

Crop factor is the ratio between a 35mm reference frame (36×24mm) and your camera's sensor, measured corner to corner. A smaller sensor captures a narrower slice of what a lens projects, so the image looks more tightly framed. Divide the full-frame diagonal — 43.27mm — by your sensor's diagonal and you have it. Micro Four Thirds measures 17.3×13mm, a 21.63mm diagonal, so 43.27 ÷ 21.63 = 2.00×.

Focal length (field of view)

Crop factor multiplies the apparent focal length. A 50mm lens on APS-C (1.53×) frames like a 76mm would on full-frame. The lens itself hasn't changed; you're just seeing a smaller patch of its image circle. Perspective stays the same, since that's a function of subject distance.

Aperture & depth of field

Aperture matters in two ways. For exposure, f/2.8 is f/2.8 on any sensor: same shutter, same ISO, same brightness. For depth of field and background blur, a smaller sensor at the same aperture gives a deeper DoF. f/2.8 on APS-C looks roughly like f/4.3 on full-frame, which is the "equivalent aperture" number this calculator shows.

ISO & exposure — a common myth

Crop factor does not change your exposure, and it does not multiply ISO. f/4 at 1/200s at ISO 400 produces the same brightness on full-frame, APS-C, or Micro Four Thirds. What does differ is the total light collected across the whole frame, which is why larger sensors tend to have cleaner high-ISO files. That's a noise question, not an exposure one.

Working backwards to a lens

Switch the calculator to I want this look and it runs in reverse: name the full-frame focal length and aperture you're after, and it tells you what to actually mount on your body. Chasing an 85mm f/1.8 portrait look on APS-C? That's a 56mm at f/1.2. Handy before you spend money.

Frequently asked questions

How do I calculate crop factor?

Divide the diagonal of a 35mm full-frame sensor (43.27mm) by the diagonal of your camera's sensor. A Canon APS-C sensor is 22.3×14.9mm, giving a 26.82mm diagonal, so 43.27 ÷ 26.82 ≈ 1.61×. Use the diagonal, not the width — width-based math happens to work for 3:2 sensors but gets 4:3 formats wrong, reporting Micro Four Thirds as 2.08× instead of the correct 2.00×.

Does crop factor make my lens longer?

Not physically. A 50mm lens is always a 50mm lens. What changes is the field of view the sensor captures: a crop sensor records a smaller rectangle out of the image the lens projects, so the scene looks more zoomed-in than it would on full-frame. You genuinely get more reach for wildlife. But the lens isn't becoming a different lens; you're just looking at a tighter crop of what it sees.

Does crop factor affect aperture or ISO?

Exposure doesn't change. f/2.8 and ISO 400 behave the same on every sensor. Depth of field does change: a smaller sensor at the same f-number gives a deeper DoF, which is where "equivalent aperture" comes in. Noise is a separate story from ISO itself; larger sensors tend to be cleaner at a given ISO because they collect more total light, but crop factor never multiplies the ISO number itself.

What lens do I need to match a full-frame look on my crop body?

Divide, don't multiply. Take the full-frame focal length you want and divide by your crop factor: a 50mm full-frame look on APS-C (1.53×) needs a 33mm lens, and 35mm is the closest thing you can buy. The same division applies to aperture if you want matching background blur, which is why crop bodies need unusually fast glass. The "I want this look" mode above does this for you.

Is a crop sensor worse than full-frame?

They're different tools, not ranked ones. Crop sensors are smaller, lighter, cheaper, and give you more effective reach at the telephoto end. Full-frame gives you a wider native field of view, shallower depth of field for the same framing, and a bit more low-light headroom. Wildlife and reach-hungry shooters often prefer APS-C; portraitists and astrophotographers often prefer full-frame.

What's the crop factor in 4K video?

It depends on the camera. Some bodies shoot 4K using the full sensor width; others read a smaller area and apply an extra crop (often 1.3–1.8× on top of the sensor's still-mode crop factor). Check your camera's spec sheet under "4K recording area" or similar.

Do mirrorless cameras have different crop factors than DSLRs?

No. Crop factor is a property of the sensor, not the mount or mirror. A Sony α6700 (mirrorless) and a Nikon D7500 (DSLR) both have 1.53× APS-C sensors and behave identically for crop factor. Mirrorless and DSLR differ in autofocus, size, weight, and lens availability, but the sensor math is the same.

Can I use a full-frame lens on a crop-sensor body (or vice versa)?

Full-frame lens on a crop body: yes, and the crop factor applies. A 50mm full-frame lens on APS-C behaves like a 76mm. You lose nothing optically; you're just using the sharpest center portion of the image circle. The other way around is trickier. Crop-sensor lenses (Canon EF-S, Nikon DX, Sony E APS-C, Fuji XF) project a smaller image circle, so on a full-frame body they'll either vignette heavily or trigger an automatic crop mode in the camera.

Do speed boosters and focal reducers change crop factor?

Yes. A focal reducer (for example, the Metabones Speed Booster) is an adapter with optical elements that compresses the image circle from a larger-format lens onto a smaller sensor. A typical 0.71× reducer turns a 1.53× APS-C crop into roughly 1.09×, close to full-frame, and gains about a stop of light along the way.