How to use the pet food transition schedule calculator
Enter the number of days you want the switch to take and the total food per day, and the tool prints how much new and old food to mix on each day. Swapping foods in one go often brings loose stool, so decide the number of days first and enter it here.
The share is an even split: the day number divided by the number of days. Advice to take 7 to 10 days over a switch is widely repeated, but no authoritative day-by-day percentage table was found, so none was invented. The formula used is printed with the result. Compiled as of October 2026.
The tool does not calculate calories and does not handle prescription-diet mixing ratios, which your veterinarian sets and you should follow as given. This tool is for reference only and does not replace veterinary care. Contact your veterinarian right away if vomiting repeats during the switch or there is blood in the stool.
Frequently asked questions
Advice to spread a switch over 7 to 10 days is common, but no authoritative table of day-by-day percentages was found. So the tool splits your chosen number of days evenly and prints the formula it used.
A common approach is to stop stepping up, go back to the previous day share and hold it for a few more days. If there is blood in the stool or vomiting alongside, contact your veterinarian.
The tool splits whatever total you enter by share, so entering cups works the same way. Just read the column headings as cups instead, since the labels print ounces.