Pet Food Portion CalculatorFree online other calculator — instant results, no sign-up
Convert a veterinarian-prescribed daily energy target into food mass.
Sign in to save results and favorites.
About the Pet Food Portion Calculator
The Pet Food Portion Calculator converts a veterinarian-prescribed daily energy target into grams of a specific food per day using its energy density. It calculates food mass rather than estimating your pet’s calorie needs. With the default inputs of 400 kcal per day and 350 kcal/100 g, the result is 114.285714 g/day.
- Prescribed daily energy (kcal)
- The veterinarian-prescribed energy amount to be supplied by this food each day, entered in kilocalories (kcal), with a default of 400.
- Food energy density (kcal/100 g)
- The energy supplied by 100 grams of the food as served, entered in kcal/100 g, with a default of 350.
Formula and method
M = (E / D) × 100; with the defaults, M = (400 / 350) × 100 = 114.285714 g/day, rounded to six decimal places.
- MDaily food mass in grams per day (g/day).
- EPrescribed daily energy supplied by this food in kilocalories per day (kcal/day).
- DFood energy density in kilocalories per 100 grams (kcal/100 g).
Divide the prescribed daily energy by the food’s energy density to find the number of 100-gram portions needed, then multiply by 100 to convert to grams per day. For the default inputs, dividing 400 by 350 and multiplying by 100 gives 114.285714 g/day when rounded to six decimal places.
Worked example
These are the calculator's starting values and the results it actually produces for them.
Inputs
- Prescribed daily energy400 kcal
- Food energy density350 kcal/100 g
Results
- Result114.285714 g/day
How to use the Pet Food Portion Calculator
- 1Confirm with your veterinarian the daily energy amount that this food should provide.
- 2Enter that amount in Prescribed daily energy (kcal); the default is 400.
- 3Check the food label or manufacturer’s information and enter Food energy density (kcal/100 g); the default is 350.
- 4Run the calculation and read the result in grams per day.
- 5Weigh the daily portion with a kitchen scale and divide it among meals according to your veterinarian’s feeding plan.
Reading your result
The result row reports the total mass of the specified food to serve over one day, not at each meal. With 400 kcal per day and an energy density of 350 kcal/100 g, Result = 114.285714 g/day. The displayed decimal places reflect arithmetic precision, not a requirement to weigh food to that precision.
Limitations
This tool does not determine calorie requirements or assess whether a food is nutritionally appropriate. It assumes the entered daily energy is to be supplied entirely by the specified food and that its energy density matches the food as served, rather than a dry-matter value. Energy density must be greater than zero, and daily energy must not be negative. Label estimates, preparation differences, and scale precision can affect the actual calories served. Treats, supplements, and other foods must be accounted for in the veterinarian’s overall feeding plan; changes in weight or health may require veterinary review.
Common questions
What if my food label lists kcal/kg instead of kcal/100 g?+
Divide the kcal/kg value by 10 before entering it. Do not enter kcal/kg directly into the kcal/100 g field.
Can I use a label that lists only kcal per cup or per can?+
You also need the grams per cup or the can’s net food mass in grams. Divide the calories per cup or can by that mass, then multiply by 100 to obtain kcal/100 g. Ask the manufacturer if the required mass information is unavailable.
Does the result include treats or a mixture of wet and dry food?+
No. The result assumes one food supplies all the entered energy. Ask your veterinarian how to allocate the daily calorie target among treats and foods, then calculate each food’s portion using its allocated calories and its own energy density.
Is 114.285714 g the amount to feed at every meal?+
No. With the default inputs, 114.285714 g is the total daily amount. Divide that daily portion among the planned meals; do not repeat the full daily amount at each meal.
Does the calculator save my information?+
Calculations run in your browser. While signed in, inputs and results are automatically recorded in account history; saving a result creates a separate saved record.
You might also like
GPA Calculator
Grade point average from letter grades and credits (grade/credits per line).
Grade Calculator
Weighted average grade (score/weight per line).
Height Calculator
Predict a child's adult height from parents' heights (mid-parental method).
Bra Size Calculator
Estimate band and cup size (US).
Dice Roller
Roll any number of dice.
Fuel Cost Calculator
Fuel cost of a trip.
Results are estimates for informational purposes and are not financial, medical or legal advice.