Sensor Size Calculator — Compare Sensor Dimensions

Crop factor is the ratio of the full-frame diagonal (43.27mm) to your sensor diagonal. APS-C has a crop factor of 1.5x (Nikon/Sony) or 1.6x (Canon). Micro Four Thirds is 2x. It tells you how much the field of view is narrowed compared to full frame. A 50mm lens on 1.5x APS-C gives the same field of view as 75mm on full frame.

Larger sensors generally produce better image quality because each pixel receives more light (larger pixel pitch), producing less noise and more dynamic range. However, modern small-sensor cameras have excellent quality — the difference is most visible at high ISO in low light. Larger sensors also produce shallower depth of field.

Medium format sensors are larger than full frame (36x24mm). Common sizes include Fuji GFX (43.8x32.9mm) and Phase One (53.4x40mm). They offer more resolution, dynamic range and shallower depth of field than full frame, but cameras and lenses are larger and more expensive.

Sensor area directly determines total light gathering capability at the same f-stop. A full frame sensor (864mm²) has 2.6x the area of APS-C (332mm²), gathering 2.6x more total light. This is equivalent to about 1.4 stops of light advantage, which explains the better high-ISO performance.