Dog Food Cost Calculator
A $90 bag can be cheaper than a $60 bag — if it's denser and feeds fewer grams. Enter the portion and the bag; get cost per day, per month, and the date the bag runs out.
Enter your dog's details
Tick 'calculate portion for me' to pull grams/day from weight and food, or type your known portion.
Feeding cost by dog size (typical kibble)
| Dog weight | Portion/day | Cost/day | Cost/month | 12 kg bag lasts |
|---|---|---|---|---|
| 5 kg | 91 g | $0.55 | $17 | 132 days |
| 10 kg | 153 g | $0.92 | $28 | 78 days |
| 20 kg | 258 g | $1.55 | $47 | 47 days |
| 30 kg | 349 g | $2.10 | $64 | 34 days |
| 40 kg | 433 g | $2.60 | $79 | 28 days |
At $6/kg food (a $72, 12 kg bag) and neutered-adult portions with 10% treat allowance removed.
Compare cost per day, or don't compare at all
Price per kilogram punishes dense foods and rewards water and air. The honest metric divides by what your dog actually eats: a 410 kcal/100 g food at $7/kg frequently undercuts a 340 kcal food at $5.50/kg on cost per day, because the dog eats ~17% less of it.
Run both foods through this calculator with your dog's portion for each (portion changes with density — the auto mode handles the standard case) and compare the monthly numbers. Then factor storage, stool quality and the dog's condition; cheapest per day is a starting point, not a verdict.
How to use this calculator
Set the daily portion
Type your dog's daily portion in grams, or use the auto option to calculate it from weight and food energy.
Enter the bag size
Enter the bag size in kilograms.
Enter the bag price
Enter what you actually pay for the bag.
Read the cost per day
Read the true cost per day and per month, and how many days the bag lasts at this portion.
Frequently asked
How long does a 12 kg bag of dog food last?
For a 20 kg dog at 258 g/day: about 46 days. A 10 kg dog stretches it to ~78 days; a 40 kg dog empties it in ~28.
How much does it cost to feed a dog per month?
At mid-range kibble prices: roughly $24/month for a 10 kg dog, $47 for 20 kg, $78 for 40 kg. Fresh subscription food typically runs 3–5× those figures.
Is expensive dog food worth it?
Sometimes — but judge by cost per day and the dog in front of you (coat, stool, weight, energy), not by bag price or marketing tier.
What does it cost to feed a medium dog per month?
At 258 g/day, a 12 kg bag lasts about 47 days. At $60 a bag: about $1.29/day, roughly $39 a month. Density rules: a denser food lasts longer even when the bag costs more.
Is the cheapest food actually cheaper?
Per bag, yes; per day, often no. Always compare cost per day at your dog's real portion, not the bag price.
Related calculators
Dog Food Calculator by Weight
Portions for every weight, 1 kg to 90 kg — table first, calculator second.
Fresh Dog Food Calculator
Fresh and gently-cooked portions by real fresh-food energy density.
Raw & BARF Calculator
Daily raw grams split into meat, bone, liver, organ and veg. BARF and PMR models.