I would rest for much longer than a week but probably more importantly you need to ask why you have such an injury and address the cause and not just the symptoms.
RICE as Tiger suggested, several times a day if you are able.
Bear in mind that the achilles tendon is the largest tendon in the body and is put under large amounts of stress in certain weight bearing activities such as running, walking, jumping etc. You don't mention if you take part in any of these, do you just cycle? Stretches - do you do any, if not then you should be?
Have you recently increased the amount of exercise or the intensity?
Don't rush to get back into your usual routine until things have improved considerably and you have addressed the other issues as you may make things considerably worse.