around 20

10-11 lumens per watt for incandescent bulbs

13-14 lumens per watt for halogen

50-60 lumens per watt for fluorescent

This question is ill posed.

Lumen is a unit of measure for how much light comes from the lamp

Watt is a unit of measure for how much energy is used by the lamp

If the question were; "Which is brighter, a 2000 lumen bulb or a 1500 lumen bulb?" then the answer would be: The 2000 lumen bulb.

I think the relation ship between lumen and watt is something like:

Incandecent bulbs are 15w/lumen

Flourecent bulbs use 40w/lumen

LED bulbs are 70w/lumen

The way to show the watt and lumen relationship is usually lumens (amount of light) per watt (energy consumption). This is like gas in your car (Miles or KM per Gallon or Liter).

Incandescent bulbs have a maximum luminosity of 52 lumens/watt.

Fluorescent bulbs range from 46 lumens/watt (CFL) to 100 lumens/watt (T5 and T8 tubes)

LED bulbs range from 29 lumens/watt (older, low efficiency) to 100+ (XCree) and they are getting better.

around 21,000 average 100 watt bulb is around 1400 lumens. That's 14 lumens per watt. 14X1,500 = 21,000