You can travel up to 30 miles in 8 hours a day in DnD 5e without risking exhaustion. This is assuming a Fast travel pace, which also gives you a -5 penalty to your Passive Perception.
However, if your party engages in a Forced March, you can continue traveling 4 miles per hour at a Fast pace. At the end of each hour past 8 hours, each party member makes a Constitution saving throw with a DC of 10 + 1 hour over 8 hours of traveling. If a character fails, it gains one level of exhaustion.
Technically, if you traveled at a fast pace for 24 hours without gaining 2 levels of exhaustion (halves your speed), you could travel 30 miles in 8 hours, plus another 64 miles in the remaining 16 hours of the day, totaling 94 miles in a day. This would be a solo mission; it’s nearly impossible for a full party to travel like this in a day.
This would be exceedingly hard to do, though, requiring both an insane Constitution saving throw modifier and lucky rolls.
Note that while mounts can gallop for double speed for up to an hour, the 30-mile limit per 8-hour day holds true whether you’re mounted or on foot. Horses only improve your overall speed if you’re able to change them regularly (every 8-10 miles), but you must be traveling in densely populated areas.
Additionally, special mounts like the pegasus or griffon can allow you travel more swiftly.
Travel Pace
Distance Traveled per…
| Pace | Minute | Hour | Day | Effect |
|---|---|---|---|---|
| Fast | 400 feet | 4 miles | 30 miles | -5 penalty to passive Wisdom (Perception) scores |
| Normal | 300 feet | 3 miles | 24 miles | – |
| Slow | 200 feet | 2 miles | 18 miles | Able to use stealth |
Note that you lose 2 miles per day from the hourly rate at a fast pace, and gain 2 miles per day from the hourly rate for slow pace. This is likely a choice from 5e’s developers to make these rules gel better with the rules for “map travel pace” in the Dungeon Master’s Guide, where hex movements are all divisible by 6.
