Calibrate or size correction X & Y?

Hi,

When printing the test cube 20x20x20 mm
When i measure the block, top middle and bottom and take average i get:
Z: 19.98mm
X: 19.5mm
Y: 19.5mm

How can i recalibrate X & Y to be more precise?
Is it in Marlin firmware settings?
Marlin%20firmware
how to calculate?
((134.74/195)*200) = 138.20
Or is it
((134.74/200)*195) = 131.37

What is correct?

Thx

Gave it both a try and 138.21 Is spot on…
So problem solved… :sweat_smile: