13.11 MPH
A pace of no less than 7:15 per mile.
The pace would be 6.32 miles per hour.
Taking 60 minutes (one hour) you divide by 7 = 8.5714 miles per hour. If he kept that pace for a marathon, he would complete the marathon in 2 hours and 48 minutes. Not world class, but a very good time for an amateur.
For your first half marathon, probably 10-13 minutes per mile, or if you are walking a little bit too, 13-16 minutes per mile. If you are a super amazing runner and/or have run a half-marathon before, then the sky's the limit.
A 4 minute 50 second mile is a pace of 12.41 miles per hour.
A 13-minute mile requires a pace of at least 4.62 miles per hour.
Your pace is 8.6 miles per hour.
A 3-minute 43.13 second mile equates to a pace of 16.13 miles per hour.
The pace must be at least 8.6 miles per hour.
You would have to keep an average pace of about 12mph (that is, miles per hour) to finish the mile in 5 minutes
60 (minutes/hour) / 9.5 (minutes/ mile) = 6.316 miles per hour