Work out fresh food cost per day by dividing the delivered price of a pack by the number of days it actually feeds your dog. You need three numbers: the delivered price, the pack size, and your dog's real daily portion. Two come from the brand. The third comes from your dog.
The only formula you need
Cost per day equals delivered pack price divided by days of feeding. Everything else is a refinement of those two terms.
Delivered price means the amount that leaves your bank account, including shipping and tax, not the headline price on the product page. If shipping is free above a threshold and you order below it, your real cost per day is higher than the sticker implies, and the gap is larger for small dogs because they make a pack last longer and order less often.
Days of feeding is where most estimates go wrong. It is not the pack size divided by a guideline portion. It is the pack size divided by the portion your dog actually eats, which depends on weight, age, neuter status, activity and whether anyone in the house adds toppers or training treats. A guideline portion is a starting point that gets adjusted within a few weeks.
Get your dog's real portion first
You cannot calculate anything until you know how much food your dog needs per day. Start with the brand's feeding guidance, feed that amount for two to three weeks without changing anything else, and weigh your dog at the beginning and at the end.
If the weight is stable and body condition looks right, that is your portion. If your dog is gaining, reduce; if losing, increase. Do it once, properly, and you will have a number you can reuse for years. Most owners who complain that fresh food is unaffordable are feeding a portion that was never checked against their own dog.
Energy needs vary widely between two dogs of identical weight, which is why guidance tables are ranges rather than prescriptions. The WSAVA global nutrition guidelines set out the body condition scoring approach vets use for exactly this adjustment, and it is worth learning because it costs nothing and it is the input every other number depends on.
Build the number step by step
Here is the whole calculation laid out. Fill in your own figures rather than borrowing anyone else's, because the answer is specific to your dog and your delivery address.
Step 7 is the one people leave out, and it is often the difference between fresh food looking expensive and looking reasonable. If you were spending money every day on toppers and broth to persuade a dog to finish a kibble meal, that spend belongs in the comparison. If you keep buying those things after switching, it belongs in the fresh number too.
The figures My Perfect Pet publishes, and the ones it does not
Be careful about where each input comes from. My Perfect Pet publishes a price on each product page and provides a weight based calculator that converts your dog's weight into a serving recommendation. It does not publish the calorie content, the guaranteed analysis or a printed feeding chart on the site itself.
That matters for step 3. If you want to calculate from calories rather than from grams, you need the calorie figure, and you will have to get it from the Nutrition Facts Sheet PDF for the recipe, from the printed pack, or by emailing the brand and keeping the reply. Do not estimate it. A calorie guess that is twenty per cent out will put your cost per day twenty per cent out in the same direction, and you will make a purchase decision on a number you invented.
For a middle of the range recipe, the Chicken and Beef Blend page will give you the price and the calculator in one place, which covers steps 1 and 3. Steps 2, 4 and 5 come from the pack and from your dog.
Sanity checks before you trust your answer
Run three checks. First, recalculate after four weeks of real feeding rather than accepting the launch estimate, because the adjusted portion almost always moves.
Second, work out cost per month as well as cost per day. A number like a few dollars a day feels small and a monthly figure feels real, and the monthly figure is the one your budget experiences.
Third, compare like with like. If you are comparing against a dry food, use the dry food's real portion too, weighed rather than scooped, and include anything you add to the bowl. Scoop measurement is consistently inaccurate, and comparing a weighed fresh portion against a generous scoop of kibble will flatter one side by a wide margin.
None of this makes fresh food cheap. It makes the number honest, which is the only useful kind. An honest number lets you decide whether to feed fresh fully, feed it as part of the bowl, or not at all, and any of those three can be the right answer.
Frequently asked questions
How do I calculate cost per day for fresh dog food?
Divide the delivered price of a pack, including shipping and tax, by the number of days that pack actually feeds your dog. Days of feeding is the total food in the delivery divided by your dog's adjusted daily portion, confirmed by weighing your dog over two to three weeks rather than by the guideline alone.
Why is my real cost per day higher than the brand's estimate?
Usually one of three reasons: shipping and tax were not in the headline price, your dog eats more than the guideline portion, or you are still buying toppers, chews and supplements alongside the food. Add all daily spend into the same number before comparing anything.
Do I need calorie information to work out cost per day?
Not if you calculate by weight of food, which is simpler and works with the portion you have already confirmed. You only need calories if you want to compare energy delivered per dollar across different foods, and in that case get the figure from the pack or the Nutrition Facts Sheet rather than estimating it.
How long should I feed a portion before deciding it is correct?
Two to three weeks, with the dog weighed at the start and the end and no other changes in the same period. Shorter than that and normal fluctuation in gut fill and hydration masks the trend you are looking for.
Is cost per day the right way to compare fresh food against dry food?
It is the right starting point, as long as both sides are measured the same way. Weigh both portions, include shipping for both, and include everything else that goes in the bowl daily. Comparing a weighed fresh portion against an unweighed scoop of dry food will always mislead.
Related reading: Calories Per Dollar: A Fairer Way to Compare Fresh Dog Food Prices, and What Fresh Feeding Costs for Two or Three Dogs, and How to Bring It Down.