MEASURING SCREEN TYPE A

This is probably the easiest screen type to measure.You just need a transparent 6" ruler which is commonly found in kids geometry set. Place it over your device screen as shown in the FIG 1. Only important thing to keep in mind is that you are measuring the screen dimensions and not the area in which screen are fixed. Align the zero reading to the left edge of the device screen and take the reading of the right edge (in above figure the reading is slightly more then 38). to allow the screen protector to fit on the screen in the above reading is reported as 38 (although it is slightly more then 38), thus the dimension A1= 38 mm, similarly dimensions A2 can be taken in vertical direction.
It is also advisable to report the dimensions 1 or 2 mm less then what it seems, like in above figure reporting 36 or 37 would be advisable as compared to reporting 38. This will take care of any reading and parallax error.

MEASURING SCREEN TYPE B
To measure this type of screen you just need a transparent 6" ruler which is commonly found in kids geometry set. Place it over your device screen at location 1 (LOC:1)as shown in the FIG 1.Only important thing to keep in mind is that you are measuring the screen dimensions and not the area in which screen are fixed. Align the zero reading to the left edge of the screen and take the reading of the right edge (in above figure the reading is slightly more then 36). To allow the screen protector to fit on the screen in the above reading is reported as 36 (although it is slightly more then 36), thus the dimension b1= 36 mm. To measure dimensions b2, place the ruler at location 2 (LOC:2) where the corner radius seems to end, and take measurements as shown above (b2=33 in above example). To measure b3 place the ruler as in location 3, aligning the zero reading with the lower edge of the screen and take the upper reading (b3=27 in above example to be on safer side although its very close to 28)
It is also advisable to report the dimensions 1 or 2 mm less then what it seems, this will take care of any reading and parallax error and ensure that supplied screen protector fits on the screen.
MEASURING SCREEN TYPE C
To measure this type of screen you just need a transparent 6" ruler which is commonly found in kids geometry set. Place it over your device screen at location 1 (LOC:1)as shown in the FIG 1.Only important thing to keep in mind is that you are measuring the screen dimensions and not the area in which screen are fixed. Align the zero reading to the left edge of the screen and take the reading of the right edge (in above figure the reading is slightly more then 36). To allow the screen protector to fit on the screen in the above reading is reported as 36 (although it is slightly more then 36), thus the dimension c1= 36 mm. To measure dimensions c2, place the ruler at location 2 (LOC:2) where the corner radius seems to end, and take measurements as shown above (c2=33 in above example). To measure c3 and c4 repeat the above procedure while placing the ruler in vertical direction.
It is also advisable to report the dimensions 1 or 2 mm less then what it seems, this will take care of any reading and parallax error and ensure that supplied screen protector fits on the screen.
MEASURING SCREEN TYPE D
Similar method as A can be applied for measuring screen type D, where screen is oval or circular insted of square or rectangle