Forensic Biology & Crime Scene Calculators

These calculators assist forensic scientists, students, and crime scene investigators in estimating time since death, blood spatter patterns, DNA contributor proportions, and other critical forensic parameters.

Quickly compute TSD using body cooling, blood spatter angle and velocity, DNA mixture proportions, luminol dilutions, contamination risk, sample degradation rates, BAC back-calculations, hair growth timelines, and serology titers.

⚠ Disclaimer: These calculators provide simplified estimates for educational and research purposes only and are not a substitute for professional forensic analysis.

Time Since Death (TSD)

Initial body temp (°C) Current body temp (°C) Ambient temp (°C)

Approx. using Newton’s cooling

Blood Spatter Angle & Velocity

Width (mm) Length (mm) Drop height (m)

Angle = arcsin(width/length), v = √(2gh)

DNA Mixture Contributor

Total peak height Contributor peak height

Contributor % = peak height / total

Luminol Working Concentration

Stock conc (mg/mL) Desired conc (mg/mL) Final volume (mL)

V1 = (C2×V2)/C1

Contamination Risk

Samples taken Contaminated samples

Risk = contaminated / total

Sample Degradation Rate

Initial quality (%) Final quality (%) Time elapsed (h)

Rate = (Q0 – Qt)/time

Alcohol BAC Back-calculation

Measured BAC (%) Time since last drink (h)

BAC ≈ measured + 0.015 × hours

Hair Growth Timeline

Hair length (cm) Growth rate (cm/month)

Time ≈ length / growth rate

Serology Titer Dilution

Initial titer Desired dilution factor

Working titer = Initial / Dilution