First of all, the correct placement of a rug depends on how big the room is and the configuration of the sofa you have. It's really important to keep the balance, and that's how...
If you have two sofas...
If you have two sofas, then the rug needs to be placed evenly between them - it should be at an equal distance from each sofa - not 10 cm in front of one and 20 cm in front of the other.
If it doesn't work properly, then it's the wrong size rug for that particular space. Take the opposite name as the target.
In a small space...
In a tight space, I like to put the rug in front of the sofa, so there is a narrow strip of flooring showing - this makes the room appear lighter and more spacious.
This also allows you to have a visual separation between the sofa and the side table - try a few of these instead of the coffee table as you will be able to see more of the rug.
In a large open space...
In a large open space, the rug should be placed under the front legs of both sofas - or if you have a large rug, then both sofas can sit completely on the rug.
If you also have chairs in the space, then the front legs of the chairs should touch or "hover" over the rug. This position creates an area of comfort without isolating the area from the rest of the room.
With modular sofas...
For modular sofas, measure the space of the rug carefully - the standard size rug is 230 cm x 160 cm, which is very difficult for a modular sofa, as it may be insufficient on both sides.
A custom rug is a better option. A large rug makes a large open space feel more intimate by connecting all the elements.
Open areas...
Rugs are the perfect tool for dividing space in an open area, whether you are defining space for a living, family or dining area.
If you're zoning your dining area (or if you're putting a rug in your dining room), choose one that's big enough for the table and all the chairs to sit completely on.