Body & Organ Weight Calculator
Calculate baseline-to-terminal body-weight change and absolute or relative organ weight.
Body & organ weight results
Enter body and organ weights.
Relative organ weight assumes a simple proportional relationship with terminal body weight. Review absolute weight, sex, age, pregnancy status, histopathology, food intake, brain ratios, and study-specific covariance analyses together. No toxicity decision is made automatically.
Source: OECD Guidance Document 150 — Guidance on Standardised Test Guidelines for Evaluating Chemicals for Endocrine Disruption.
Tool Guide
Definition
Body & Organ Weight Calculator — Calculate absolute and percent change from baseline to terminal body weight, then normalize absolute organ weight to terminal body weight as mg/g, g/100 g, and percent.
Purpose
(1) Cross-check body-weight change in repeat-dose studies (2) Summarize absolute and relative organ weight together (3) Prevent g/kg and mg/g unit errors (4) Support subject-level QC or report-table calculations
How to Use
① Enter baseline and terminal body weight with a shared unit. ② Enter the absolute organ weight and its unit. ③ Copy body-weight change, mg/g, and g/100 g values. The denominator is terminal body weight. Do not interpret toxicity from relative weight alone; review absolute weight, histopathology, and study design together.
Examples
Example) Baseline body weight=300 g, terminal=270 g, organ=1.35 g → body-weight change=−30 g, −10% → absolute organ=1.35 g → organ/body=5 mg/g=0.5 g/100 g=0.5% Relative organ weight assumes simple proportionality and does not produce an automatic toxicity decision.