Do I need the JR pass

Hello, my partner and I are going to Japan for 2 weeks. Our trip looks like this - Tokyo 5 nights, Osaka 4 nights, back to Tokyo for 5 nights then fly home. We will be doing 2 day trips one to Nara and one to Kyoto whilst in Osaka. My question is should we get the JR Pass and if so should we get the 7 day or 14 day? We are trying to limit our costs so we weren�ft going to get the JR until we realised it was about the same cost to travel to Osaka as it is for the JR pass.

Also will we need the JR pass to get from Narita airport to Tokyo and vice versa?

Thank you

A seven day pass only just pays off in your case. And wont cover the NE'X. A 14 day pass would be overkill and more expensive than you travels, unless you have a trip to Hiroshima in their you failed to mention.

To save costs, get buses between Narita and Tokyo for 900-1000 yen. And Platt Kodama discount tickets for 10,100 yen between Tokyo and Shin-Osaka. Both options are an easy search on google.

Get the Japanican eVoucher for Tokyo-Osaka return for Y23,000 and do single tickets - cheaper.
If you get the 7-day pass, it will cover the Y27,200 round trip to Osaka and the Y1600 to Nara and the (maybe) 1000 yen to Kyoto. But it also covers the other inevitable trips you will make on JR trains within 7 days, and provides flexibility to visit other places you might like to go but otherwise excluded.