Angle of Impact Calculator
Calculate the angle of impact from bloodstain dimensions. Used in forensic science to determine the trajectory of blood droplets.
How to Use This Calculator
- Enter the stain length (longer dimension) in millimeters.
- Enter the stain width (shorter dimension) in millimeters.
- The calculator displays the angle of impact in degrees and radians.
- Use this for forensic analysis or understanding bloodstain patterns.
Angle of Impact Formula
The angle is calculated from stain dimensions:
Example: 15mm length, 5mm width: Angle = arcsin(5/15) = arcsin(0.333) = 19.5°. A 90° angle (perpendicular) creates a circular stain (width = length). Lower angles create elongated stains. The calculator uses this formula to determine impact angle from bloodstain measurements.
Full Description
The Angle of Impact Calculator determines the angle at which a blood droplet struck a surface, based on the bloodstain\'s dimensions. This is a fundamental calculation in forensic bloodstain pattern analysis (BPA). When blood strikes a surface at an angle, it creates an elongated stain—the more horizontal the impact, the more elongated the stain.
The angle of impact is calculated using the formula: Angle = arcsin(Width / Length). The width is the shorter dimension of the stain, and the length is the longer dimension. A 90° angle indicates a perpendicular impact (dropped straight down), creating a circular stain. Lower angles indicate more horizontal trajectories, creating elongated stains. Forensic analysts use this information to reconstruct crime scenes, determine the point of origin of blood spatter, and understand the sequence of events.
This calculator helps you determine angle of impact from bloodstain measurements. Enter stain length and width, and it calculates the angle in degrees and radians. Use it for forensic analysis, crime scene reconstruction, understanding bloodstain patterns, or educational purposes. Remember, this is a simplified calculation—real forensic analysis considers many additional factors!
Frequently Asked Questions
What is angle of impact?
Angle of impact is the angle at which a blood droplet strikes a surface, measured from the surface. It's calculated from the stain's length and width. A 90° angle (perpendicular) creates a circular stain. Lower angles create elongated stains. Used in forensic science to determine bloodstain trajectory.
How is angle of impact calculated?
Angle = arcsin(Width / Length). The width is the shorter dimension, length is the longer dimension. Example: 15mm length, 5mm width: Angle = arcsin(5/15) = arcsin(0.333) = 19.5°. The calculator uses this formula to determine impact angle.
What does the angle tell us?
The angle indicates the trajectory of the blood droplet. 90° = perpendicular impact (dropped straight down). Lower angles = more horizontal trajectory. Forensic analysts use this to reconstruct crime scenes, determine point of origin, and understand bloodstain patterns.
What are typical angle ranges?
90°: Perpendicular impact (circular stain). 60-89°: Steep angle (slightly elongated). 30-59°: Moderate angle (elongated stain). 10-29°: Shallow angle (very elongated). <10°: Very shallow (extremely elongated, rare). Most bloodstains fall between 30-90° in typical scenarios.