For the sake of simplicity and meaningful distinctions, convert all ranges into the following categories. This especially works well for theater of mind.
3 ft (1 m), but defaults 5 ft, adjacent
10 ft (3 m), melee, reach, 5-step
30 ft (10 m), near, move, throw, close
100 ft (30 m), farspell
300 ft (100 m), bowshot, city block, field
1000 ft (300 m), max bowshot
3000 ft (1 km)
In practice, the ranges that matter are:
Anything beyond near is "far". It may or may not be on a battle map grid if using minis.
Round off all far ranges up to 60 feet, such as 35, 40 and 50, to 60 feet, and treat as two moves.
Farspell. Many distant spells reach about 100 feet. Round off all spell ranges at 80, 90, or 120 (namely more than 60 but less than 200) to 100 feet.
The bowshot at 300 feet represents the extreme range of a battle. Treat all spell ranges that are 200 to 1000 as equivalent to a bowshot. A bow can shoot within 300 feet without disadvantage.
Max bowshot. It is possible but disadvantageous to hit a target up to 1000 feet. In reallife, it is possible for an arrow to go beyond 1000 feet, but there are no known records of an archer hitting a target at 1000 feet. Some have come close, in the 900s. So the number 1000 feet is excellent as the extreme limit for a bowshot that is at disadvantage.
The bowshot and the max bowshot rarely happen during gameplay. But they are useful conceptual distances when spotting something in the distance.