21 mm to Inches on a Ruler
21 millimeters is equal to 0.8 inches on a ruler.
The place marked in red shows 0.8 inches, which is equal to 21 millimeters on the ruler.
Try these similar conversions:
22 mm to inches on a ruler
Convert 22 millimeters to inches and see it on a ruler.
20 mm to inches on a ruler
Convert 20 millimeters to inches and see it on a ruler.