How much time should we allow to get from Stanstead A/port to Heathrow A/port? Does anyone know the easiest and quickest way?
Thanks.

National Express is one of the quickest and probably the cheapest. See nationalexpress.com . See how long they expect the route to take, and double it to be sure.

A private car transfer service will cost upwards of £80 and require at least 2 hours depending on time of day. I wouldn't plan for any less than 3 though; the M25 is the busiest highway in Europe, maybe the world.

I agree that a National Express coach is your best choice. Be sure to allow a minimum of five hours (preferably more) between your scheduled arrival at one airport and your scheduled departure from the other. A late arrival, a delay in getting through customs, or heavy traffic can use up your margin in a hurry.

You could take the train from Stansted to London and then the tube to Heathrow in a little over 2 hours. I would add an extra hour to be safe.

Wouldn't it be nice if someone would fly between those two places?