The focal length comparison calculator shows the angle of view, full-frame equivalent, and ideal subject distance for any lens/sensor combination. Compare how the same focal length behaves on full-frame, APS-C, and Micro Four Thirds sensors.
Compare Focal Lengths
How to Compare Focal Lengths Across Sensor Sizes
The same physical focal length produces different fields of view on different sensor sizes. A 50mm lens on a full-frame camera looks "normal" (similar to human vision), but on an APS-C camera (1.5× crop) it behaves like a 75mm short telephoto — perfect for portraits.
Practical Focal Length Guide
On full-frame: 14-24mm = ultra-wide landscape/architecture, 35mm = environmental portrait/street, 50mm = natural perspective, 85-135mm = flattering portrait, 200-400mm = wildlife/sports, 500mm+ = birds/distant subjects. On APS-C, divide the focal length by your crop factor to find the equivalent in this guide.
Frequently Asked Questions
What is crop factor?
Crop factor is the ratio of a sensor's size to a full-frame (35mm) sensor. APS-C sensors have a 1.5× (Nikon/Sony) or 1.6× (Canon) crop factor, and Micro Four Thirds have 2×. A 50mm lens on APS-C behaves like an 75mm on full-frame in terms of angle of view.
What is angle of view?
Angle of view describes how much of a scene the lens captures, measured in degrees. A 14mm wide-angle captures about 114° horizontally. A 50mm standard lens captures about 47°. A 200mm telephoto captures only 12°. Wider angle = more scene, narrower angle = more reach/compression.
What focal length is best for portraits?
85-135mm on full-frame (or equivalent) is ideal for flattering portrait compression with comfortable subject distance. On APS-C, 50-85mm gives similar results. Shorter lenses (35-50mm) require close proximity and can distort facial features slightly.
What focal length do I need for landscapes?
Wide-angle lenses (14-35mm full-frame equivalent) are standard for landscapes. Ultra-wide (14-20mm) creates dramatic foreground interest. Standard (35-50mm) produces a more natural, 'human eye' perspective. Telephoto (100-200mm+) compresses distant layers like mountains.
Is this free?
Yes, completely free. All calculations run in your browser with no data collected.