For the x, y, z steps per millimeter print out a 20x20 cube. Use calipers and measure, I ended up with the following values x 20.01mm, y 20.00 mm, z: 19.90 mm

These are all good but Z could use a little adjustment. The formula for getting the new value is below. Steps per mm is 400 by default, use M503 command to view current steps.

(CURRENT * EXPECTED) / MEASURED = NEW
(400 * 20 / 19.9) = 402.01
(93 * 100 / 87.5) = 106.28

To set in marlin use M92 Z402. The same formula can be used for extruder steps per mm. I extruded 100mm and measured 87.5 instead. I put these values in Simplify3D Script tab along with their other default G-code

G28 ; home all axes
M92 Z402 E106; calibration values
G1 Z5 F3000 ; lift
G1 X5 Y10 F1500 ; move to prime
G1 Z0.2 F3000 ; get ready to prime
G92 E0 ; reset extrusion distance
G1 Y80 E10 F600 ; prime nozzle
G1 Y100 F5000 ; quick wipe