Quick answer: Agra to Mathura is 69.6 km by road via NH 44, around 1 hour 39 minutes by car. Vrindavan is a further 12 km, 25 to 35 minutes. One day is possible; 2 to 3 days covers the full circuit. Start with the Taj Mahal, which is closed on Friday.
If you are working out how far in advance to plan a trip to Mathura Vrindavan, the honest answer is that none of the sources I used gives a...