The RER × factor calculator: 70 × (kg)^0.75 times the life-stage factor — the arithmetic behind every honest feeding chart, with worked examples and adjustment rules.
| Item | Detail |
|---|---|
| RER formula | 70 × (weight in kg)^0.75 |
| Neutered adult | × 1.6 | Intact adult: × 1.8 |
| Weight loss | × 1.0 of ideal weight (never current) |
| Puppy 4–12 mo | × 2.0 | Working hard: × 2.0–5.0 |
| Adjustment | BCS each point off ideal ≈ ±10% calories |
Worked examples
40 lb (18.1 kg) neutered: RER ≈ 722 → × 1.6 ≈ 1,155 kcal/day. Overweight 70 lb Lab (ideal 65): RER at ideal ≈ 1,190 → × 1.0 = 1,190 kcal for loss. Working Border Collie 40 lb in season: × 2.5 ≈ 1,800 kcal. The cup table converts to grams for your formula.
The correction loop
The calculator is the start; the monthly BCS score is the correction. Feed the number for two weeks, score, adjust ±10% per point off ideal — three cycles calibrate any dog precisely. Treats ride inside the total (our budget sheet).
FAQ
What factor do I use for a neutered house dog?
1.6. Intact dogs multiply by 1.8; weight-loss programs use 1.0 × ideal weight.
Does the calculator work for puppies?
Use × 2.0 for 4–12 months with puppy-formula charts — growth curves need the breed-size formulas in our age guides.
Related reading: Cup table · BCS card · Treat sheet · Library