Every calorie calculation on this site ends the same way: divide the daily calories by how many calories are in the food. Which means that if the energy density is wrong, the gram figure is wrong — no matter how carefully you did everything before it.
Dry dog foods commonly run anywhere from about 3,300 to 4,200 kcal/kg. Using a default when your actual food sits at the other end of that range moves the answer by roughly a quarter.
How we label our evidence
- Source-supportedStated directly in the cited institutional publication.
- Our editorial guidanceA conservative reading of the evidence applied to a caregiver decision. Not a validated clinical protocol.
- Evidence gapWe could not verify this in our approved sources, so we have not invented a number.
Where the number is
Look for a metabolisable energy (ME) statement, usually on the side or back of the bag near the nutritional adequacy statement. It is generally expressed as kcal/kg, and often also per cup or per can.
If you find kcal per cup but not per kilogram, use the manufacturer's website or contact them — cup weights vary by kibble shape and density, so converting from a cup figure yourself introduces exactly the error you are trying to avoid.
Our defaults, and what they are for
The calculator pre-fills a value when you pick a food type. These are mid-range figures intended to get you a reasonable answer before you go and find the bag — not a substitute for it.
| Food type | Dog | Cat |
|---|---|---|
| Dry | 3,800 | 4,000 |
| Wet | 1,100 | 900 |
| Semi-moist | 2,800 | 2,900 |
| Freeze-dried | 4,800 | 5,000 |
Note how far apart wet and dry sit. The same dog needs roughly three to four times the gram weight of wet food as dry — which is why the food-type selector changes the headline number so dramatically, and why it is worth setting correctly.
Then weigh the food
Having gone to the trouble of getting an accurate energy density, don't hand the accuracy back at the last step. Measuring cups are off by 30% or more depending on how the kibble settles and what shape it is. A kitchen scale costs very little and removes the single largest source of error in day-to-day feeding.
This is also why we report the answer in grams rather than cups, and why grams stay grams even when you switch the weight unit to pounds.
The field is under "Refine the estimate" in the dog and cat calculators. Pick the food type first — it resets the number — then type your bag's value over it.
Sources
- AAFCO Reading Labels
- WSAVA Global Nutrition Committee Guidelines on Selecting Pet Foods (PDF)
- Pet Nutrition Alliance Calculating Calories Based on Pet Needs