LR44 vs 357 vs 303
Three codes for one 11.6 × 5.4 mm footprint. LR44 is alkaline at 1.5 V; 357 and 303 are both silver oxide at 1.55 V and now largely sold as a single dual-marked cell.
All three are the same size and all three will fit. The LR44 is the cheap alkaline one at 1.5 volts. The 357 and the 303 are both silver oxide at 1.55 volts, hold a steadier voltage and last longer — and today they are effectively one cell, usually sold marked “357/303”. So the real decision is only between two things: alkaline for a toy or a calculator, silver oxide for a watch, a light meter or anything that takes readings.
- Verdict:
- One size, two chemistries — the 357 and 303 are the same cell
Side by side
| Specification | LR44 | 357 | 303 |
|---|---|---|---|
| Chemistry | Alkaline | Silver oxide | Silver oxide |
| Nominal voltage | 1.5 V | 1.55 V | 1.55 V |
| Size | 11.6 × 5.4 mm | 11.6 × 5.4 mm | 11.6 × 5.4 mm |
| Capacity | 110–130 mAh | 150–190 mAh | 150–175 mAh |
| IEC code | LR44 | SR44W | SR44SW |
| Originally built for | General use | High drain | Low drain |
| Relative cost | Low | Higher | Higher |
It is really a two-way choice
357 and 303 are both the SR44 in silver oxide — the codes once separated high-drain from low-drain construction, and most manufacturers now build one cell that does both and print both numbers. Treat them as one option.
Alkaline against silver oxide
The LR44 starts at 1.5 V and sags steadily. The silver oxide pair hold close to 1.55 V until they are spent, and carry around 50% more energy. That flat curve is the whole reason watches and meters specify them.
All three fit, so decide on the device
The shared 11.6 × 5.4 mm footprint means no fit question arises. Cheap and disposable, take the LR44. Anything that measures something, take the silver oxide.
Check before you swap. Batteries with similar dimensions are not always interchangeable. Always verify voltage, chemistry and the requirements printed in your device manual before fitting a replacement.