Why the Numbers Look Slightly Different
Veterinary medicine commonly uses a quick mental conversion of 2.2 lb per kg, and that approach is clinically appropriate in many day-to-day situations. You may notice that Shepherd’s calculations sometimes reflect a slightly different number. This is intentional.
The technical standard vs clinical shorthand
Technical standard
Shepherd uses the international SI (metric) standard for weight conversion:
1 kg = 2.20462 lb
1 lb = 0.453592 kg
This is the exact, globally defined conversion used in medical software, scientific research, pharmacology references, and regulatory documentation.
The clinical shorthand
In clinical practice, many veterinarians are taught to use:
1 kg ≈ 2.2 lb
This rounded number is a practical shorthand that works well for mental math, teaching, and routine clinical decision-making.
Why Shepherd uses the exact value
Both approaches are valid, but they serve different purposes.
Clinically correct: 2.2 is appropriate for quick estimates and everyday reasoning
Technically correct: 2.20462 is required for consistent, repeatable calculations in software
Because Shepherd performs automated calculations, dosing support, reporting, and analytics, it uses the exact SI conversion to ensure accuracy and consistency across patients, records, and time.
Does this affect patient care?
In most cases, the difference is extremely small and does not change clinical decisions. For example, a 100-lb dog converts to:
45.45 kg using 2.2
45.36 kg using 2.20462
That difference is negligible for most medications and recommendations. Shepherd’s approach using the exact conversion is designed to support accuracy, safety, and consistency.