Lumens are the best way to measure brightness because it literally is brightness.
With traditional bulbs, they often rated them by watts. Watts measure energy use, not light output. And with LED, wattage no longer matters as it once did. Instead, you’ll see newer technology listing out brightness, or how many lumens it produces.
LED is more efficient than metal halide lights. Therefore, if you were to replace a 1,000 watt metal halide light with a 1,000 LED, the light could be drastically different. Instead, you’ll want to focus on the number of lumens produced by the traditional bulb, and match that with LED technology if you’re okay with the light output.
Of course, parking lot lights work a bit differently than light bulbs you’d place in your home.
We usually recommend two LED Parking Lot Light heads of 20,000 lumens each at about 15-20 feet high on each pole. Space the pole about 20 feet apart. That is average lighting. Go brighter and higher if you want your space more illuminated If you go up to 30 feet and do 2 light heads at 30,000 or 40,000 each, you can space the poles 30-40 feet apart.
Every light fixture operates differently. And different LED products produce light in different ways. Your goal is probably a mixture of energy savings and light improvement, so it’s important to select the most efficient light for the job.
Again, these are just some ideas. There are so many variables in lighting that you have to decide what your goals are ahead of time. Decide if you need it adequate or bright. Determine what your options are with installation.