Lens Focal Length & Crop Factor Calculator

What crop factor actually means

A 50mm lens is ALWAYS a 50mm lens — the physical focal length doesn't change. What changes is the angle of view captured when paired with smaller sensors. A 50mm on full-frame sees the world the way a 50mm "should" (similar to human vision). The same 50mm on APS-C captures only the center of that frame, equivalent to a 75-80mm full-frame view.

Common crop factors

• Full-frame (Sony A7, Canon R5, Nikon Z7): 1.0x — the 35mm reference standard
• APS-C Sony/Nikon/Fuji: 1.5x — 50mm acts like 75mm full-frame
• APS-C Canon: 1.6x — 50mm acts like 80mm
• Micro Four Thirds (Olympus, Panasonic GH): 2.0x — 25mm acts like 50mm
• 1-inch (Sony RX100, RX10): 2.7x — 18mm acts like 50mm

Lens type by equivalent focal length

• 14-24mm equivalent: Ultra-wide. Landscapes, architecture, astro.
• 24-35mm equivalent: Wide. Street, documentary, environmental portrait.
• 35-50mm equivalent: "Normal" — closest to human vision.
• 50-85mm equivalent: Short tele. Standard portrait range.
• 85-135mm equivalent: Classic portrait. Compressed perspective, flattering.
• 135-300mm equivalent: Telephoto. Sports, wildlife approach.
• 300mm+ equivalent: Super tele. Distant wildlife, surveillance.

Crop factor and aperture

The crop factor also affects depth of field — a 50mm f/1.8 on APS-C gives roughly the same depth of field as a 75mm f/2.7 on full-frame. This is why full-frame portraits look noticeably more "blurry background" than APS-C portraits at equivalent framing.

For tested cameras and lenses, see our photography reviews.