# Pet Food Calculator

Calculate how much to feed your dog or cat. Get daily calories, cups of dry food, wet food cans, and monthly cost based on pet weight, age, and activity.

## What this calculates

Feeding the right amount is one of the most important things you can do for your pet's health. This calculator uses the veterinary Resting Energy Requirement (RER) formula to determine your dog or cat's daily calorie needs, then converts that to practical portions of dry or wet food.

## Inputs

- **Pet Type** — options: Dog, Cat
- **Pet Weight** (lbs) — min 1, max 250
- **Life Stage** — options: Puppy / Kitten, Adult, Senior
- **Activity Level** — options: Low (sedentary, indoor), Moderate (daily walks), High (working, very active)

## Outputs

- **Daily Calories** — Recommended daily caloric intake.
- **Dry Food Per Day** — formatted as text — Approximate dry food (~110 g per cup, ~375 kcal).
- **Wet Food Per Day** — formatted as text — Approximate wet food (~370 g per can, ~375 kcal).
- **Monthly Food Cost** — formatted as currency — Estimated monthly cost using mid-range food.

## Details

The calculation starts with the Resting Energy Requirement (RER), the standard veterinary formula:

  - RER = 70 x (body weight in kg)^0.75

  - Daily calories = RER x activity factor (1.2 to 3.0 depending on age, species, and activity)

Activity factors vary by life stage and energy level. Puppies and kittens require 2.5-3x RER for growth. Active working dogs may need 2x RER, while senior indoor cats may only need 1.1x RER. Neutered or spayed pets may need slightly less than intact animals.

Standard dry dog and cat food provides approximately 350-400 calories per cup, though this varies significantly by brand and formula. Always check the specific calorie content on your pet food packaging (listed as kcal/cup or kcal/can) and adjust portions accordingly. A kitchen scale provides the most accurate measurements, since cups can vary depending on kibble size and how full you pack them.

## Frequently Asked Questions

**Q: How do I know if I am feeding my pet the right amount?**

A: Monitor your pet's body condition. You should be able to feel (but not prominently see) their ribs. They should have a visible waist when viewed from above and a tucked abdomen from the side. If your pet is gaining or losing weight, adjust portions by 10-15% and reassess in 2-4 weeks.

**Q: Should I feed my pet wet or dry food?**

A: Both are nutritionally complete when they meet AAFCO standards. Dry food is more economical and better for dental health. Wet food provides more moisture, which benefits cats especially. Many pet owners use a combination. Consult your veterinarian for specific recommendations.

**Q: How often should I feed my pet?**

A: Adult dogs do well on 2 meals per day. Puppies under 6 months need 3-4 meals daily. Adult cats can be fed 2-3 times daily or have dry food available for free-feeding if they self-regulate well. Senior pets often do better with smaller, more frequent meals.

**Q: Why does this calculator use the RER formula?**

A: The Resting Energy Requirement (RER = 70 x weight_kg^0.75) is the standard veterinary formula used by the American Animal Hospital Association and most veterinary nutritionists. It accounts for the non-linear relationship between body size and metabolic rate, so larger animals need fewer calories per pound than smaller ones.

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Source: https://vastcalc.com/calculators/everyday/pet-food
Category: Everyday Life
Last updated: 2026-04-21