Armor plate data
Settings (leave at default if uncertain)
Angle type
Calculation type


You can use the form below to calculate the relative armor thickness of a sloped armor plate.

You can specify two angles. If you specify only one, leaving the other at 90, the direct relative armor thickness will be calculated. If two angles are specified, a compound angle will be calculated. This is useful for simulating a vehicle with sloped armor that is shot at from an angle, or a vehicle with armor plates sloping in more than one dimension.

The default sine option measures the angle in degrees from the angle of the incoming shot. In other words, 90 degrees is vertical, and 0 degrees is horizontal. The cosine option use the angle of the slope of the armor plate from vertical.

You can use the calculation type option to change from the normal calculation, which calculates the relative thickness based on the actual thickness and a slope, to a reverse calculation, which calculates the actual thickness based on a known, relative thickness and slope.

Note that the armor thickness must be entered without the unit, e.g., 100 rather than 100 mm. Fractions must be converted to decimal numbers, e.g., 0.375 rather than ⅜.

Additional Reading

Relative armor thickness
Information about the importance of sloped armor on armored vehicles.