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✂️ Crop Factor Calculator
Find your camera’s crop factor, full-frame equivalent focal length, equivalent aperture, and diagonal angle of view — all from one sensor selection, instantly.
Sensor area view: the blue rectangle shows how much of a full-frame scene your sensor actually captures. The smaller the box, the more your lens’s field of view gets “cropped” in.
What Is Crop Factor?
Crop factor is the number that tells you how much smaller your camera’s sensor is compared to a full-frame 35mm sensor, and therefore how much narrower your lens’s field of view becomes. It’s calculated by dividing the diagonal measurement of a full-frame sensor by the diagonal measurement of your own sensor. A full-frame sensor is the industry’s 1.0x reference point; anything smaller carries a crop factor greater than 1.0, and anything larger — like medium format — carries a crop factor below 1.0.
The concept trips up a lot of photographers because it feels like the lens is “zooming in” on smaller sensors, but that’s not actually what happens. The lens projects the exact same image circle regardless of what’s behind it. A smaller sensor simply captures a smaller slice from the center of that circle, which produces the visual effect of a tighter, more telephoto-looking frame — without the lens’s true focal length changing at all.
Full Sensor Size & Crop Factor Reference Table
| Sensor Format | Approx. Diagonal | Crop Factor |
|---|---|---|
| Medium Format (53.7×40.4mm) | 67.1 mm | 0.64x |
| Medium Format (44×33mm) | 55.0 mm | 0.79x |
| Full Frame / 35mm | 43.3 mm | 1.0x (reference) |
| APS-H | 33.5 mm | ≈1.3x |
| APS-C (Nikon / Sony / Fujifilm) | 28.4 mm | ≈1.5x |
| APS-C (Canon) | 26.7 mm | ≈1.6x |
| Micro Four Thirds (M4/3) | 21.6 mm | 2.0x |
| 1-inch sensor | 15.9 mm | ≈2.7x |
| 1/1.7-inch (premium compacts) | ≈10.8 mm | ≈4.0x |
| 1/2.3-inch (most phones/compacts) | ≈7.7 mm | ≈5.6x |
These are the exact multipliers this calculator applies. Note that some manufacturers publish slightly different figures for their own sensors (Canon’s APS-C, for instance, is sometimes listed as 1.62x rather than 1.6x), so always check your specific camera’s spec sheet if you need lab-grade precision.
How the Crop Factor Formula Works
The math behind this calculator comes down to two formulas that photographers reuse constantly:
- Crop Factor = Full-Frame Sensor Diagonal ÷ Your Sensor Diagonal
- Equivalent Focal Length = Actual Focal Length × Crop Factor
So if you’re shooting with a 50mm lens on a Nikon APS-C body (1.5x crop factor), the math is simply 50 × 1.5 = 75mm. That 75mm figure is the full-frame equivalent — it tells you that your APS-C camera with a 50mm lens frames a scene the same way a 75mm lens would frame it on a full-frame body, standing in the same spot.
Equivalent Aperture and Depth of Field — What Most Calculators Skip
Field of view isn’t the only thing crop factor changes. It also affects how a photo’s background blur (bokeh) compares across formats, even though the lens’s actual f-stop and exposure never change. This calculator includes an optional aperture field precisely so you can see this second layer that many simpler crop-factor tools leave out entirely.
The formula is: Equivalent Aperture = Actual Aperture × Crop Factor. A 50mm f/1.8 lens on an APS-C body (1.5x) frames like a 75mm lens and produces depth of field similar to a 75mm f/2.7 lens on full frame. Your exposure — the actual brightness of the image at a given ISO and shutter speed — is completely unaffected. Only the visual depth of field changes, because that depends on the physical size of the aperture opening relative to the sensor capturing it.
Diagonal Angle of View
The calculator also reports the diagonal angle of view, which is the actual angular width of the scene your lens-and-sensor combination captures. It’s computed with:
Angle of View = 2 × arctan( Sensor Diagonal ÷ (2 × Focal Length) )
This number is especially useful when comparing gear across brands, because “35mm equivalent” language can get confusing fast, while an angle in degrees is unambiguous — a 27° diagonal angle of view is the same 27° no matter what camera produced it.
Worked Examples
| Sensor | Lens | Crop Factor | Full-Frame Equivalent |
|---|---|---|---|
| APS-C Nikon/Sony/Fuji | 35mm | 1.5x | 52.5mm |
| APS-C Canon | 50mm | 1.6x | 80mm |
| Micro Four Thirds | 25mm | 2.0x | 50mm |
| 1-inch sensor | 24mm | 2.7x | 65mm |
| Medium Format 44×33 | 80mm | 0.79x | 63mm |
Why Crop Factor Matters for Photographers and Videographers
🎯 Buying the Right Lens
A 35mm lens sounds wide-angle by full-frame standards, but on an APS-C body it behaves like a 50–52mm standard lens instead. Knowing this before you buy prevents an expensive mismatch between the field of view you expected and the one you actually get.
🦁 Wildlife & Telephoto Reach
Crop sensors are popular with wildlife and sports shooters precisely because the “extra reach” is free — a 300mm lens on a 1.5x APS-C body frames like a 450mm lens on full frame, without buying a longer, heavier, and far more expensive telephoto lens.
🎬 Multi-Camera Video Matching
When a production mixes a full-frame cinema camera with an APS-C or Micro Four Thirds B-camera, matching the field of view between them is essential for continuity. Knowing each camera’s crop factor lets a DP choose the right focal lengths on both bodies so cuts between them look seamless.
🌄 Landscape and Wide-Angle Work
Crop sensors work against you when you want an ultra-wide look, since every lens effectively gets “longer.” Landscape photographers on APS-C or M4/3 bodies often need to budget for genuinely wider lenses to compensate.
📱 Comparing Phones and Compacts
Smartphone sensors typically carry a crop factor around 5–7x, which is why phone camera specs often list a “full-frame equivalent” focal length like 24mm or 26mm for what is physically a much shorter lens.
Common Misconceptions About Crop Factor
- “Crop sensors zoom in more.” They don’t magnify anything — they simply record a smaller portion of the same image the lens always projects.
- “Crop factor changes my exposure settings.” It doesn’t. ISO, shutter speed, and aperture for correct exposure stay the same regardless of sensor size; only field of view and depth of field shift.
- “All APS-C sensors have the same crop factor.” They don’t — Canon’s APS-C sensors use roughly 1.6x, while Nikon, Sony, and Fujifilm APS-C sensors use roughly 1.5x.
- “A crop sensor is strictly worse than full frame.” It’s a trade-off, not a downgrade — crop sensors are smaller, lighter, cheaper, and offer effectively “free” telephoto reach, at the cost of shallower low-light performance and depth-of-field control.
Frequently Asked Questions
It converts your lens’s actual focal length into its full-frame equivalent, and also shows equivalent aperture and diagonal angle of view, based on your camera’s sensor size.
No, crop factor only affects field of view and apparent depth of field — not optical quality. Smaller sensors can, however, show more noise at high ISOs due to smaller individual pixels.
Yes — select the 1/2.3-inch option (or enter a custom crop factor if you know your phone’s exact sensor size) to see the full-frame equivalent of its lens.
Check your camera manufacturer’s official specification sheet for the sensor’s physical dimensions, or use the “Custom Crop Factor” option in this calculator if you already know the number.
Not exactly. Canon’s APS-C sensors typically use a 1.6x crop factor, while Nikon, Sony, and Fujifilm APS-C sensors use approximately 1.5x. This calculator lets you pick the correct one.
No. The same ISO, shutter speed, and aperture give a correctly exposed image regardless of sensor size. Only the framing and apparent depth of field change.
It shows how much background blur (depth of field) you’d need on a full-frame camera to match what a crop sensor produces at the same aperture — useful for comparing bokeh across formats.
Yes, but it works in reverse — since their sensors are larger than full frame, their crop factor is below 1.0x, meaning lenses appear wider than their stated focal length would suggest on full frame.
Because the sensor only records the central, most magnified part of the lens’s image circle, a shorter and cheaper telephoto lens on a crop body can match the reach of a much longer, pricier lens on full frame.
Yes — it’s completely free, with no login and no limits on how many times you can use it.
Final Thoughts
Crop factor is one of those numbers that quietly shapes almost every decision you make about lenses, framing, and gear — yet it’s rarely explained with the full picture. This calculator goes beyond a single focal-length conversion by also showing you the equivalent aperture and diagonal angle of view, so you can walk away with a complete, accurate sense of exactly how your camera and lens combination will actually see the world.
