CR2032 vs CR2025 vs CR2016: Button Cell Size and Capacity Guide

CR2032, CR2025 and CR2016 look almost identical. All three are 20 mm in diameter, all three deliver 3.0V, and all three are lithium button cells. Yet they are not interchangeable, and using the wrong one is one of the most common battery mistakes. The difference is thickness, and thickness decides both fit and capacity.

Reading the numbers

In the CR series, the first two digits give the diameter in millimetres and the last two digits give the thickness in tenths of a millimetre. CR2032 is 20 mm across and 3.2 mm thick. CR2025 is 20 mm across and 2.5 mm thick. CR2016 is 20 mm across and 1.6 mm thick. The numbering is a size code, not a performance rating, and it applies across the whole CR range: CR2450 is 24.5 mm across and 5.0 mm thick, CR2477 is 24.5 mm across and 7.7 mm thick, and CR927 is 9.5 mm across and 2.7 mm thick.

Capacity follows thickness

Because the diameter is the same, the thicker cell holds more active material and therefore more capacity. The source table lists CR2032 at 210 or 220 mAh in two table rows, CR2025 at 150 mAh and CR2016 at 75 mAh. A device designed for a CR2032 will run roughly three times as long on its intended cell as it would on a CR2016, if the thinner cell could be fitted at all — which, in a holder designed for 3.2 mm, it usually cannot, because the contacts will not press firmly against a 1.6 mm cell.

The reverse mistake is just as common: forcing a CR2032 into a holder designed for a CR2016. The holder will not close, the device case may bulge or crack, and the contacts may be damaged. The rule is simple: match the full model number, not just the diameter.

Which one does your device need

The device manual or the marking inside the battery compartment gives the answer. If the marking says CR2032, use CR2032. If it says CR2025, use CR2025. If the old cell is still available, read its number directly. Do not substitute on the assumption that a thicker cell is better or that a thinner cell will do: the holder, the contacts and the device's current draw were all designed around a specific thickness and capacity.

For devices where the manual is lost, measure the old cell: diameter with a ruler or caliper, thickness the same way, and match both figures to the table. A 20 mm cell measuring 3.2 mm thick is a CR2032; at 2.5 mm it is a CR2025; at 1.6 mm it is a CR2016.

Other sizes in the same family

The same logic covers the rest of the CR range. CR2450 at 24.5 by 5.0 mm and 600 mAh suits larger devices that need more energy, such as sensors and medical monitors. CR2477 at 24.5 by 7.7 mm and 900 mAh suits devices with room for a thick cell and a long service requirement. Smaller cells such as CR1632 at 16.0 by 3.2 mm and 120 mAh suit compact devices such as car keys and small remotes. The full source table covers CR927 through CR3032.

Ordering notes

Important note from the source catalogue table: capacity, size and weight for button cells are stated to be subject to the final datasheet, and must be confirmed before mass production. This guide preserves that note. When ordering, confirm the model number, the thickness, whether tabs or leads are required, and the quantity. Cells are available with tabs or leads for OEM assembly. Minimum order value is USD $500, according to the company FAQ, and samples are available. Certificates are available upon request.

Related pages: Button Cell Size Guide, CR2032, CR2025, CR2016, CR2450, CR2477.

Beyond the 20 mm trio: the wider button cell range

The 20 mm trio is the most visible part of the button cell range, but the full CR range in the source table runs from CR927 at 9.5 by 2.7 mm and 30 mAh up to CR3032 at 30.0 by 3.2 mm and 500 mAh. Between those extremes sit CR1216 at 12.5 by 1.6 mm and 25 mAh, CR1220 at 12.5 by 2.0 mm and 40 mAh, CR1225 at 12.5 by 2.5 mm and 50 mAh, CR1616 at 16.0 by 1.6 mm and 50 mAh, CR1620 at 16.0 by 2.0 mm and 70 mAh, CR1632 at 16.0 by 3.2 mm and 120 mAh, CR2050 at 20.0 by 2.5 mm and 150 mAh, CR2320 at 23.0 by 2.0 mm and 130 mAh, CR2325 at 23.0 by 2.5 mm and 190 mAh, CR2330 at 23.0 by 3.0 mm and 260 mAh, CR2430 at 24.5 by 3.0 mm and 270 mAh, CR2450 at 24.5 by 5.0 mm and 600 mAh, and CR2477 at 24.5 by 7.7 mm and 900 mAh. The numbering rule is the same throughout: the first two digits give the diameter in millimetres, the last two give the thickness in tenths of a millimetre.

That range exists because small devices vary enormously in the space they offer. A car key may accept only a 16 mm cell. A medical monitor may have room for a 24.5 mm cell. A backup memory circuit may need only a tiny CR927. The selection rule never changes: match the full model number, including thickness, and confirm the figure against the final datasheet before mass production, as the source table note requires.

Tabs, leads and OEM assembly

Many button cells are not fitted by the end user at all. They are soldered or clipped into a product during manufacturing, and for those uses the cell is ordered with tabs or leads already attached. The source category page states that button cells are available with tabs or leads for OEM use, and that the range includes standard CR cells, special button cells and button cells with leads or solder tabs. For an OEM order, the tab or lead configuration is part of the specification, alongside the model number and the quantity, and it should be confirmed with the same care as the size. A cell with the wrong tab layout cannot be assembled, even if its diameter, thickness and capacity are all correct. Samples are available for qualification before a bulk order, minimum order value is USD $500 according to the company FAQ, and lead time is confirmed per order.

For a buyer ordering button cells in bulk, the practical next step is a sample order: cells of the exact model and thickness the device requires, including the tab or lead configuration where the cell is soldered into the product. Samples are available, minimum order value is USD $500 according to the company FAQ, and lead time is confirmed per order. A sample test confirms fit in the holder, contact pressure, and voltage under the device's load — the three things that decide whether a button cell works in practice, whatever the catalogue says.