I usually use a rule of thumb that a light’s maximum practical range is about equal to the ANSI beam distance in meters changing “Meters” to “feet”. In other words a 200 Meter ANSI beam distance would be good up to about 200 feet. If you wanted to keep everything in Meters, you would divide the ANSI number by 3.28.
Probably a better method is to use civil twilight, which is about 3.2 Lux; to get this you divide the ANSI beam distance by 3.6. Or you can just divide by 4 to make it simple for a approximation.