Do not solve the whole room with one lumen total. Plan the light that must reach each task surface, then add a softer ambient and decorative layer.
Move beyond wattage
Wattage describes energy use, not brightness. Lumens are the more useful comparison for lamp and fixture output, while lux describes the amount of light reaching a surface.
Fixture optics, mounting height, wall colour, shade material, and room geometry all change how useful those lumens feel.
Plan by activity
A passage route, a kitchen worktop, a reading chair, and a dining table need different amounts and distributions of light. Identify the task plane first, then select fittings that deliver light to it without uncomfortable glare.
Dark finishes absorb more light. Rooms with deep wall colours or high ceilings often need more delivered output than similarly sized pale rooms.
Add the layers separately
Estimate task, ambient, and decorative light as separate systems. This prevents a decorative pendant from being overpowered simply because it is expected to illuminate every corner.
Manufacturer photometric files and beam information are more reliable than comparing headline lumen numbers between fittings with very different optics.
Design for range, not one level
Daylight, age, activity, and time of day all change the comfortable level. Dimming and separate circuits create range without forcing every source to operate at full output.
When the plan is complex or architectural, a lighting calculation from a qualified designer can test the result before ceilings and wiring are closed.