What battery does a key fob take?
Most car key fobs use a CR2032. Some models use CR2025 or CR2016. Check the inside of the fob cover to confirm.
Most common answer
The majority of car key fobs from major manufacturers use a CR2032. This includes many Toyota, Honda, Ford, BMW, and Volkswagen models from 2005 to the present.
How to identify yours if you're unsure
- Open the key fob using a coin in the slot or a small flathead screwdriver along the seam.
- Look at the battery label printed on the existing cell — the code is stamped on the face.
- Match it to the reference page below.
If the battery is missing its label, measure it: 20mm diameter = CR20xx family. Measure thickness to determine CR2032 (3.2mm), CR2025 (2.5mm), or CR2016 (1.6mm).
Measurement guide
Any ruler or small calipers will measure diameter and thickness. The "CR" prefix always means 3V lithium. The four digits = diameter + thickness in tenths of a millimeter.