Apple
Apple Watch 40mm Band Size & Fitting
The 40mm Apple Watch (SE and Series 4–6) takes bands from the small family: 38mm, 40mm and 41mm bands all fit.
Lug fitting40mm band
| Strap fitting | 40mm band |
|---|---|
| Case size | 40 mm |
| Lug-to-lug | — |
| Thickness | — |
Which model do you have?
Similar-looking models can take different bands. Your model and case size are on the box, your receipt or the watch's settings.
| Model | Case | Band |
|---|---|---|
| Apple Watch 40mm (SE, Series 4–6) | 40mm | Small: 38/40/41mm |
| Apple Watch 41mm (Series 7–9) | 41mm | Small: 38/40/41mm |
| Apple Watch 42mm (Series 10/11) | 42mm | Small: 38/40/41/42mm |
| Apple Watch 44mm (SE, Series 4–6) | 44mm | Large: 42/44/45/46/49mm |
| Apple Watch 45mm (Series 7–9) | 45mm | Large: 42/44/45/46/49mm |
| Apple Watch 46mm (Series 10/11) | 46mm | Large: 44/45/46/49mm |
| Apple Watch Ultra | 49mm | 49mm, or 44/45/46mm |
Strap styles that fit
- Brand / OEM strapMade for this exact model.
- Adapter + standard strapBuy a model-specific adapter first.
- NATO / pass-throughNo standard lugs to pass through.
- 2-piece leatherNeeds an adapter to fit.
- Rubber / FKMOEM or adapter only.
- Metal braceletModel-specific bracelet only.
▲ Small band family: 38, 40 and 41mm bands fit.
Fit & sizing notes for the Apple Watch 40mm
- What to buy: straps made for the Apple Watch 40mm, or an adapter kit for this exact model. A normal-width strap won't attach on its own. Our integrated & smartwatch strap guide explains the options.
- Adapters stick out past the case, so the watch wears longer; check the adapter's output width before buying straps for it.
- Every Apple model: see our Apple Watch band size guide for which bands fit each one.
Sources & corrections
Fitting checked against: Apple: Change your Apple Watch band. Last checked 24 October 2026.
Spec wrong for your watch? Send us a correction with your reference number.
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Apple Watch 40mm — band questions
What strap size does the Apple Watch 40mm take?
The 40mm Apple Watch (SE and Series 4–6) takes bands from the small family: 38mm, 40mm and 41mm bands all fit.
Can I put a normal NATO or leather strap on it?
Not directly. A standard strap won't attach on its own. Where a model-specific adapter exists, fit that first and then a normal strap of the adapter's width.
Where can I buy straps that fit the Apple Watch 40mm?
Search for straps and adapters made specifically for the Apple Watch 40mm; generic sizes won't clip in without one.