Can I use my UK driving licence in the US?

Yes you can; legally speaking you only need a valid license and a passport. Hire companies may have their own individual rules about how long you need to have held your license for. This will vary from one hire company to another, and if UK companies are anything to go by, you might struggle to find one given your limited driving experience.

It’s also reccommended (but not compulsory) to get an International Driving Permit which you can get from the AA. Phone them or email them, ask for an application form. You’ll need a passport-type photo, a copy of your driving license. Cost is less than £10 (depends on the postage plan you pick) and it takes about 10 days for it to be sent on. The IDP is not compulsory for the USA but it does help eliminate hassle from traffic cops who don’t know the rules.

http://www.theaa.com/getaway/idp/index.html

https://www.theaa.com/common/contact_us_form.jsp

And if by hire a car, you mean rent one… some companies won’t rent a car to someone under the age of 25, and if they do, it’s a good deal extra. From experience. And American car rentals aren’t really all that cheap either. Depending on how long you intend to be here, you might actually be better off buying a cruddy used car, which you can sell before you go back home and get some of that money back (assuming it’s still working lol).

Or depending on where in the US you go, you might really be doing yourself a favor to put some heavy research into public transportation.

It is very difficult and expensive to rent a car if you are under the age of 25. :(

I was thinking about buying a car if i couldnt rent one do you think I could buy an old banger for around $1000? The internship last for 4 months and is apparently out in the sticks a bit in maryland. the website says your own transport is highly reccommended so i have a feeling like public transport will be few and far between. plus if i am doing research i wont want to be taking biological field equipment including buckets etc on a bus!
at least running my car out there wont be as expensive as the UK, petrol costs around £1.29/L which is around £5.80 a gallon or $8.80/G if i have done my calculations correctly

You could buy a beat up car for about that, depending on where you will be in the US. Good enough to get you around for that long, anyway.

I agree with the others, if you’re staying 4 months, it’ll be cheaper to buy a car than hire one.

My dad got lucky and found me a minivan for $350. A repair cost $300, it lasted for 7 months, and although it was falling apart by then, the junkyard paid him $200 for it because it still ran (technically). If you look hard enough, you can find things like this easy.

I’m using my UK driving license in the US this month. But I’m over 25 so not sure how difficult it is if you’re under that age… Also – additional drivers on rental cars are free if it’s in California! Woo!
Good luck with your internship!