5-6 hrs at Frankfurt Airport
 

For a 5P flight from Frankfurt to US, can we check luggage at 11A, and have enough time to take taxi for a quick tour? If so, what time should we be back if our luggage is already checked in ... 1.5 hrs or more?

We would have another flight into Frankfurt at 10A that same day.

Thanks

Yes, you can. And you even can take the S-Bahn which is cheaper, quicker and will make you more familiar with Frankfurt directly to Hauptwache into the heart of the city. 12 minutes.... 1 1/2 hour is certainly sufficient. I normally arrive one our ahead of my flight and still need to check in. However, what you can do is a search. You are not the first member to ask these questions.

Does it make sense to get into town if I arrive at 4pm (from IST) and have a flight to SIN at 10:10pm?

Are the stores open?

I'm with 2 kids (4 & 6 yrs old), any suggestions or is it just roaming around/shopping?

Sure, take S8/9 in the direction of Hanau and get off at Hauptwache. Shops are open till 8pm (closed on Sunday).