* Diameter: CR1032: 10.0 mm, CR1025: 10.0 mm
* Height: CR1032: 3.2 mm, CR1025: 2.5 mm
* Capacity: CR1032: 230 mAh, CR1025: 150 mAh
* Voltage: CR1032: 3.0 V, CR1025: 3.0 V
As you can see, the two batteries are the same diameter, but the CR1032 is thicker than the CR1025. The CR1032 also has a higher capacity than the CR1025.