Food transition calculator
Switching foods? See how much old and new food goes into the bowl on each day of the switch – for dogs and cats.
Per day, all meals together
From day 7: new food only
1⅞ cups
Still 665 kcal a day – same as today.
| Days | Share new | Old food | New food |
|---|---|---|---|
| Days 1–2 | ¼ | 1⅜ cups | ½ cup |
| Days 3–4 | ½ | ⅞ cup | 1 cup |
| Days 5–6 | ¾ | ½ cup | 1⅜ cups |
| Day 7+ | all | – | 1⅞ cups |
Amounts are per day. Split them across meals as usual.
If your pet needs more time, stay on a mix for a day or two longer.
Diarrhea or vomiting? Ask your vet.
Why split by calories, not cups?
Foods differ in calories; wet food often has only a quarter of the calories of dry food. If you split the cups or grams, your pet would get too much or too little during the switch. So the calories stay the same and we work out the amounts. That’s how the nutritionists at Tufts University calculate it too.
The short answer
Switch food over about a week: days 1–2 ¼ new food, days 3–4 half and half, days 5–6 ¾ new, from day 7 only the new one (Hill’s 7-day plan). Split the calories, not the cups. Example: a dog gets 1¾ cups of food with 380 kcal/cup today, and the new food has 350 kcal/cup. That’s 1⅜ cups old + ½ cup new on days 1–2 and 1⅞ cups new from day 7.
Questions
How long should you take to switch food?
About a week. Hill’s gives 7 days, the nutritionists at Tufts University at least a week, and Purina 7–10 days for cats. If your pet needs more time, stay on a mix longer.
Why does the amount change?
Because the new food has different calories. Your pet should get the same calories per day as now: fewer kcal per cup means more cups, more kcal means fewer.
Does the plan work for cats and puppies?
Yes, the stages are the same. For puppies and kittens the daily amount changes as they grow, so use today’s amount from the puppy or kitten calculator.
What if my pet gets diarrhea during the switch?
Ask your vet. We can’t tell from here what’s behind it.
Related
- Switching food: the 7-day planA sudden switch can upset the stomach. Switching slowly means a little more new food and a little less old food over about a week.
- Dog food calculatorDaily amount for your dog – from weight and your food.
- Cat food calculatorDaily amount for your cat, wet food included.
- Mixing wet and dry food for dogsEnter the weight, both foods and the split. The calculator splits calories, not weight, so the amount is right.