How to set exact measurements?

I am Sketchup beginner. The problem is that I can’t fix the measurements for let’s say a floor. I can use the scale tool and the measurement tool but still I can’t create a floor that have the exact measurements that I want.

When I use the scale tool the measurements flips around beyond control. When I set the exact measurements using the measurement tool the actual measurements of the floor does not follow what I set.

Very frustrating. I have read the manual but I need some advice.

There is not a “measurement tool”, I suspect you are talking about the tape measure tool, but that is not where you should be starting.

Start by modeling a rectangle to exact measurements. Choose the rectangle tool, click once to start a rectangle and move the mouse in any direction, now, let go of the mouse and type 3m,4m DO NOT CLICK INTO the value control box where the measurements appear, just type, SketchUp is always listening. If you are already working in a meters template then you just need to type 3,4 and hit return. (If you use a euro keyboard setup there is a chance your dimension separator is a semicolin ; )The rectangle is completed and sized correctly, you can type new dimensions until you start another operation, then they are set.

To change the size of existing things you use the scale tool or the move tool. The scale tool will accept either a scale factor such as 1.5 or 2.0, or it will accept absolute numbers like 18m. The green handles let you scale in only one or multiple directions.

You can also select individual lines and move them with the move tool to change the size of surfaces.

Here are some places to start. If you have a specific problem the post a screen shot or your downloaded model for us to see.

Thank you so much for sharing