How do I tell if a laptop supports dual band Wifi?

Most of the laptops I see have their wireless spec stated as "802.11b/g/n". Does this say if the laptop supports dual band or not?

If the laptop description doesn't say if it's dual band or not, how else can I tell?

 

Check out the laptop's detailed specs, get the name of the WiFi card you're using, then look up that card.

 

Usually dual band will be designated as a/b/g/n. n can be either though, so it's not always 100% true.

 

You also make sure that the router is capable of dual band as well.
This may also will help for Intel cards: Intel® Wireless Product Selection Guide
Intel® Wi-Fi Products

 

This is the tricky part wifi card must say dual band or listed 2.4/5ghz bands to be true dual band card. So read carefully.

Intel isn't the only dual band card here and since we have no detail information from the OP that is speculation as to what dual band they are talking about. So they need to list for us the Laptop to be sure it can use dual band in the first place.

Both of these two conditions must be met for your to have dual band wifi one less and your either 2.4ghz or 5ghz band.

 

The a designation is a giveaway that it can do 5 GHz, what I meant is that I've seen b/g/n cards that had the dual band designation or didn't, but were still dual band in some specs. If it says a/b/g/n though...

 

Agreed, also as mentioned before, look up the name on the WiFi card from the specs and verify it with the manufacturers website. Hope this helps.