Is 4 hours of layover enough for 2 seperate bookings in LHR (and some more)?

I am flying from Stuttgart to San Francisco next year. I booked the two legs separately so STR-LHR with British Airways and LHR-SFO with Virgin Atlantic. Reasoning is that it was cheaper by around 40% of the price.

The flight STR-LHR is scheduled to be in London 4 hours and 15 minutes before my departure to SFO. This also applies to the return-flight. I probably will need to go from Terminal 5 to Terminal 3.

Will this time be more than sufficient to reach my next flight? If the flight from LHR-SFO gets cancelled, will I not get a refund of my ticket? If the flight from Stuttgart to London will be cancelled, I will not get any refunds for the SFO leg, right?

I only have hand-luggage with me.

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How much time should you have between layovers?

In general, Owens recommends allowing yourself at least two hours between flights if you're traveling from or connecting in a city that's prone to delays and your layover is in a large airport; and one hour if the layover is in a small airport.

Is 3 hours enough for a layover?

Re: Is 3 hour layover long enough to catch a connection? Yes, three hours is more than enough time, assuming both the flights are on one ticket. You could absorb a fairly lengthy delay on the inbound of up to 2 hours and still make the flight to SNN.

Do I have to check in twice if I have a layover?

In general, if you're on a domestic flight, once you land for your layover, you'll pass through a transfer area that will take you to the gate for your next flight without having to check in again. Your bags will automatically pass through to the next flight without you having to collect them.

How short of a layover is too short?

In most cases, a 30-minute layover for domestic flights and an hour for international flights is considered a minimum, or short, layover.

How to Book Multiple Flights on One Trip with Long Layovers for Maximum Savings

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