Crop Factor

Micro Four Thirds Equivalent Focal Length

Convert a Micro Four Thirds lens to its full-frame-equivalent field of view using the format's 2× crop factor. The calculator starts with a 25mm Micro Four Thirds lens beside a 50mm full-frame lens.

Compare Micro Four Thirds with full frame

Change any focal length or crop factor to compare the resulting field of view.

Example scene: Den Haag Skyline
  • Lens A: 50mm
  • Lens B: 50mm
Lens A
Prime
Focal length
Sensor
Full frame · 1×

Sony α7, Nikon Z6/Z8, Canon EOS R, Panasonic S, Leica SL

Effective50mm × 1
50mm
Lens B
Prime
Focal length
Sensor
Micro Four Thirds · 2×

OM System / Olympus, Panasonic Lumix G & GH

Effective25mm × 2
50mm
Effective = focal length × crop factor

Where your lenses land

Lens A: 50mm full-frame equivalent
Lens B: 50mm full-frame equivalent
Architecture, ≤35mm: no lens
Landscape, 14–50mm: covered by Lens A, Lens B
Street, 24–50mm: covered by Lens A, Lens B
Travel, 24–85mm: covered by Lens A, Lens B
Portrait, 50–135mm: covered by Lens A, Lens B
Wildlife, 135mm+: no lens
Full-frame equivalent · log scale

How the conversion works

Micro Four Thirds cameras from OM System/Olympus and Panasonic use a 2× crop factor for full-frame field-of-view comparisons. Multiply the focal length on the lens by two.

For example, a 25mm Micro Four Thirds lens frames like a 50mm lens on full frame. This equivalence describes framing only; exposure settings and the lens's physical focal length do not change.

Micro Four Thirds lens focal length × 2 = full-frame-equivalent focal length

Focal length conversion table

Micro Four Thirds focal lengths and their full-frame field-of-view equivalents
Micro Four Thirds lensFull-frame-equivalent field of view
16mm 32mm
24mm 48mm
35mm 70mm
50mm 100mm
85mm 170mm
200mm 400mm

To work backward from full frame, divide by two: a 24mm full-frame view needs about a 12mm Micro Four Thirds lens.

Worked example: a 12–40mm zoom

A 12–40mm Micro Four Thirds zoom covers a field-of-view range similar to a 24–80mm lens on full frame: 12 × 2 = 24 and 40 × 2 = 80. The lens remains a 12–40mm lens, but the equivalent range makes cross-system framing easier to compare.