This question seem open ended because it was not specific. However, it takes an average of 7-10 minutes to cover a 4 miles journey depending on your drive speed. Whilst, it takes an average of 80-84 minutes of walk to complete a 4 miles distance.
Minutes and miles measure quite different things. If you are talking about a specific speed, use the formula: distance = speed x time.
Set it at 7 mph
to give you an idea about 4miles, but could alot more could be alot less depending on fitness.
4 miles=7040 yards
4 mile = 253 440 inch
7 040 yards = 4miles
7040 yards 7040 yards
roughly 1 1/4miles