Original instructional diagram for Feline Body-Proportion Measurements: Landmarks Matter More Than Decimal Places. Values, when shown, are illustrative; clinical images do not recommend a dose.
Use the specified landmarks and centimeters
The feline proportion equation depends on the rib-cage circumference and a defined lower hind-leg measurement. Substituting overall body length or mixing inches with centimeters changes its meaning. Recheck a surprising result before interpreting it.
Use Cat BMI Calculator to work through these inputs while keeping the displayed assumptions in view.
A body-proportion estimate is not a diet plan
The estimate is neither human BMI nor a complete assessment of a cat’s health. Individual conformation and measurement technique affect it. Do not set a food restriction from the number alone; clinical evaluation and a suitable feeding plan are separate tasks.
This question belongs to the Cat calculators group within Biology calculators.
Read the calculation on its stated basis
Proportion estimate = ((rib circumference / 0.7067 − lower-leg length) / 0.9156) − lower-leg length. Both measurements are in centimeters.
This proportion-based estimate is not human BMI. No diet or obesity diagnosis is generated.
Retain the input definitions and units with the result. A later comparison should use the same basis; a change in method is a new scenario, not simply a more precise version of the old number.
Keep related questions separate
Cat Calorie Calculator addresses a related part of the measurement or interpretation task. Check its own method before carrying a value from one tool to the other.
For a related perspective, read Cat Energy Estimates: The Multiplier Does Not Diagnose a Feeding Need.
For tools in other subjects, return to GreenCalc. Keep the calculator result with its assumptions rather than using a link or a matching unit as evidence that two models are interchangeable.
By GreenCalc · Updated 2026-11-05