ShootCalc

Crop Factor Calculator

Convert focal lengths and apertures across sensor sizes. Enter your lens and see the full-frame equivalent field of view and depth of field instantly.

Your setup

Crop factor: 1.5×

mm
f/

Equivalent focal length

52.5mm

35mm on APS-C Nikon → Full Frame

Crop factor

1.5×

your sensor · target: 1.0×

Equiv. aperture

—

for same DoF

Diag. angle of view

43.9°

35mm on APS-C Nikon

DoF advantage

0.6 stops

target has shallower DoF

Sensor size comparison

APS-C NikonFull Frame

This lens across all sensors

35mm on APS-C Nikon

SensorCrop35mm equiv.Equiv. apertureAngle of view
Full Frame (35mm)1.0×52.5mm—63.4°
APS-C Nikon / Sony / Fuji(your sensor)1.5×35mm—43.9°
APS-C Canon1.6×33mm—41.9°
Micro Four Thirds2.0×26.5mm—34.4°
1-inch sensor2.7×19.5mm—25.5°
1/2.3" (compact / drone)5.6×9.5mm—12.7°

What is crop factor?

Crop factor — also called the focal length multiplier — is the ratio between the diagonal of a 35mm full frame sensor and the diagonal of your camera's sensor. A larger sensor captures a wider slice of what the lens sees. A smaller sensor captures only the centre portion, effectively "zooming in" compared to what the same lens would show on full frame.

The most common example: mount a 50mm lens on an APS-C camera with a 1.5× crop factor, and the field of view matches what a 75mm lens would show on a full frame body. The physical lens hasn't changed — only the portion of its image circle you're using.

Crop factor and depth of field

Field of view equivalence is straightforward, but depth of field equivalence is not. To produce the same depth of field on a target sensor as your current setup, the aperture must be scaled by the same ratio.

An f/2.8 lens on APS-C (1.5×) produces a depth of field equivalent to f/4.2 on full frame — meaning full frame has a real advantage for shallow depth-of-field work when matched for field of view. Conversely, smaller sensors require you to stop down more to match full frame depth of field, which means less background blur, all else being equal.

Common crop factor values

APS-C sensors from Nikon, Sony, Pentax, and Fujifilm use a 1.5× crop; Canon's APS-C is slightly smaller at 1.6×. Micro Four Thirds sensors from Panasonic and Olympus/OM System have a 2× crop factor. Medium format sensors from Fujifilm GFX and Hasselblad have a crop factor below 1× (i.e. larger than full frame), giving wider fields of view from the same physical lens.

The maths

The equivalent focal length on any target sensor is:

fequiv=factual×CFsourceCFtargetf_{\text{equiv}} = f_{\text{actual}} \times \frac{CF_{\text{source}}}{CF_{\text{target}}}

Where,

  • factualf_{\text{actual}} — the physical focal length marked on your lens (mm)
  • CFsourceCF_{\text{source}} — the crop factor of the camera the lens is mounted on
  • CFtargetCF_{\text{target}} — the crop factor of the sensor you are comparing to

So a 35mm lens on APS-C (CFCF = 1.5) compared to full frame (CFCF = 1.0) gives 35×1.51.035 \times \tfrac{1.5}{1.0} = 52.5mm equivalent. Moving to a larger sensor reduces apparent focal length; moving to a smaller sensor multiplies reach.

The diagonal angle of view is derived from the sensor's physical diagonal and the focal length:

AoV=2arctan⁡ ⁣(d2f)\text{AoV} = 2 \arctan\!\left(\frac{d}{2f}\right)

Where,

  • dd — sensor diagonal in mm (e.g. 43.3 mm for full frame)
  • ff — the physical focal length in mm

To produce the same depth of field on a target sensor, the aperture must be scaled by the same ratio:

Nequiv=Nactual×CFsourceCFtargetN_{\text{equiv}} = N_{\text{actual}} \times \frac{CF_{\text{source}}}{CF_{\text{target}}}

How to use this calculator

  1. 01Select your camera sensor — the body the lens is physically mounted on. The crop factor for that sensor appears below the dropdown.
  2. 02Enter the physical focal length printed on your lens — not the "35mm equivalent" if one is quoted. For a zoom, enter the focal length you are shooting at.
  3. 03Optionally enter your aperture. This unlocks the equivalent aperture result, which tells you the f-number needed on the target sensor to match the same depth of field.
  4. 04Choose a sensor to compare to. The calculator shows the equivalent focal length, aperture, and angle of view on that sensor. The sensor diagram shows the relative physical sizes side by side.
  5. 05The all-sensors table below the main results shows how your lens behaves across every sensor format at once — useful for comparing systems or planning a lens purchase.

FAQ

What is crop factor?

Crop factor is the ratio of a 35mm full frame sensor's diagonal (43.3mm) to your sensor's diagonal. An APS-C sensor (Nikon/Sony/Fujifilm) has a diagonal of around 28.4mm, giving a crop factor of 43.3 ÷ 28.4 ≈ 1.5×. A smaller sensor "crops" more of the lens's image circle, which makes lenses appear to have more reach.

Is 50mm on APS-C the same as 75mm on full frame?

In terms of field of view, yes — a 50mm lens on APS-C (1.5× crop) gives the same angle of view as a 75mm lens would on full frame. However, depth of field will differ: the 50mm at f/1.8 on APS-C will have slightly more depth of field than a 75mm f/1.8 on full frame would, because the physical lens geometry still differs even if the framing matches. To get truly equivalent depth of field, you'd need the APS-C lens at f/1.2 (to match a full frame 75mm f/1.8).

Does crop factor affect exposure?

No. Exposure — the relationship between f-number, ISO, and shutter speed — is the same on every sensor format. An f/2.8 exposure is the same brightness on an APS-C body as on a full frame body. Crop factor only affects field of view and depth of field, not the amount of light hitting each photosite.

What crop factor does Canon APS-C use?

Canon APS-C bodies (Rebel series, 90D, R7, R10, etc.) use a 1.6× crop factor. Most other APS-C manufacturers — Nikon, Sony, Fujifilm, Pentax — use a 1.5× crop. The difference is small in practice: a 50mm lens gives 80mm equivalent on Canon APS-C vs. 75mm equivalent on other APS-C cameras.

Does a crop sensor give less background blur?

When comparing equivalent setups (same field of view, same subject distance), yes — a larger sensor produces shallower depth of field and more background blur. To match full frame background blur on APS-C, you need an aperture that is 1.5× wider. So to match f/1.8 on full frame, you would need roughly f/1.2 on APS-C. This is why full frame cameras are often preferred for portrait work.

Do crop sensor cameras give you more reach for wildlife or sports?

From the same shooting position with the same lens, yes — a 1.5× crop sensor frames more tightly, effectively multiplying the lens's reach. A 400mm lens becomes equivalent to 600mm. However, this is a trade-off: you also lose the wider field of view at the other end of a zoom, and the sensor's pixel density determines whether the apparent reach translates into real resolution.

Related tools

Depth of Field Calculator

Near/far focus limits, total DoF, and hyperfocal distance. Includes a live focus zone diagram.

↳ 50mm · f/2.8 · 3m → DoF 0.43m

Golden Hour Calculator

Find golden hour, blue hour, sunrise, and sunset times for any location and date. Includes a live sun arc diagram.

↳ London · Jun 21 → golden at 21:08

ND Filter Calculator

Calculate the new shutter speed for any ND filter. Or reverse it — enter a target exposure and find the filter you need.

↳ 1/500s + ND64 → 1/8s