Sensor size comparison
Choose two sensor formats. The diagram draws both at their true relative size, centred on the lens axis, and the table lists every measured and computed value.
How to read the result
Area difference is B relative to A: a negative value means B is smaller. The crop ratio in the last column is how much tighter the same lens frames on B than on A. Because both sensors share the lens axis, the diagram shows exactly which part of A's image B would record.
Aspect ratio matters when the formats differ in shape. A 4:3 sensor compared with a 3:2 sensor is taller relative to its width, so the two crops cannot line up on every edge at once.