Carb Calculator

[Airway]

I found this calculator while researching food. I haven't checked it for accuracy.
http://scheyderweb.com/cats/catfood.html

 

[Chris & China (GA)]

A lot of us use that to get a general idea if a good is going to be in the right ballpark or not, but it uses Guaranteed Analysis numbers (which unfortunately is all most pet foods give us) so it's not exact

GA number just give you the minimums and maximums.....it might say the fat is minimum of 5% but that doesn't mean it's not 10, 12 or 25%

 

[Elizabeth and Bertie]

I found this calculator while researching food. I haven't checked it for accuracy.
http://scheyderweb.com/cats/catfood.html

Yes, this is a helpful little tool.

The calculation isn't exactly the same as the usual formula used here, but it's close.
I think it uses a multiplier of 8.7 for fat (to calculate calories) rather than the usual 8.5, but this only makes a tiny difference.
And it doesn't go so far as to calculate the percentage of calories from carbs, but you can do this last bit of the calculation yourself.

Using the results of the Sheyderweb calculation you just grab a calculator and do this:
Divide the 'calories from carbs per 100g' by the 'total calories per 100g', and then multiply by 100. That should give the 'percentage of calories from carbs'.

Incidentally, I do have a very basic Excel spreadsheet that does the entire calculation. If you'd like me to email it to you just PM me your email address.

As Chris says above though, the 'Guaranteed Analysis' on the label gives possible minimum and maximum values for the food. To know what's really in the can at any given time you'd need to contact the manufacturer and ask for the current 'as fed' values. (Occasionally, these are on the manufacturer's website too.)
If you can't get the current 'as fed' values, then a calculation using the GA values, plus a thorough read of the ingredients list (to check for carb sources), could still give you enough information to enable you to decide whether the food is worth trying or not. Ultimately, 'the proof of the pudding is in the eating', of course. But fortunately, those of who hometest can see the effects of the foods we're feeding! (We're very lucky aren't we? )

Note for Europeans: Cat foods in Europe usually use 'Typical Analysis' rather than 'Guaranteed Analysis' and these figures are more reliable for doing calculations. So, Europeans shouldn't need to 'go through the same hoops' as US folks in terms of trying to get the current data (unless they're feeding US manufactured foods of course.... )

Eliz