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Birds • nutritionVerified Scientific Formula

Bird Basal Metabolic Rate (BMR & Energy) Calculator

Computes daily basal metabolic calories for pet birds, companion parrots, and wild avian species.

Enter Parameters

g
Calculated Output
Estimated Daily Maintenance Energy (MER)
20.9kcal/day13.9 kcal/day Basal Metabolic Rate (BMR)
What This Result Means
For a 100g (3.53 oz) bird, basal resting metabolism is ~13.9 kcal/day; daily active maintenance requirement is ~20.9 kcal/day.
Calculation Details & Practical Equivalents
Maintenance Energy (1.5× BMR)
20.9 kcal/day
Basal Metabolic Rate (BMR)
13.9 kcal/day
Body Weight in Ounces
3.53 oz
Allometric Multiplier (K)
78

Formula & Mathematical Methodology

Standard Mathematical Formula
Non-Passerine BMR = 78 × (BW in kg)^0.75 | Passerine BMR = 129 × (BW in kg)^0.75

Formula Variables Defined

BWBird Body Weight(grams or kg)

Avian body mass

OrderPasserine vs Non-Passerine

Passerines have ~1.6× higher basal metabolic rate

Step-by-Step Calculation Example

Example: 100g Cockatiel (Non-Passerine)

A 100-gram companion cockatiel.

  1. Weight in kg = 100g ÷ 1,000 = 0.100 kg
  2. 0.100^0.75 = 0.1778
  3. BMR = 78 × 0.1778 = 13.9 kcal/day
  4. Maintenance (1.5×) = 20.8 kcal/day
Final Output: 13.9 kcal/day BMR (Maintenance: ~20.8 kcal/day)

Key Assumptions

  • Bird in thermal neutrality.

Biological Limitations

    Verified Scientific & Veterinary Sources

    Version: 1.0•Methodology Reviewed: 2026-01-22
    1. The Merck Veterinary Manual (11th Edition)textbook
    Aiello, S.E. and Moses, M.A. (Eds.) (2020). Merck & Co., Inc., Kenilworth, NJ
    Access Source Authority

    Bird Basal Metabolic Rate (BMR & Energy) Calculator — FAQs

    Passerines (songbirds, finches, canaries) have significantly higher body temperatures (~106-108°F) and faster basal metabolic turnover than non-passerines.

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