One hundred grams of a product labelled 80% fat contains 80 g fat. A product entered as 100% fat would supply that fat mass in 80 g. This is the narrow calculation performed by the Whatson Butter/Oil Fat Equivalent tool.
It also reports the nonfat material removed or introduced. That result matters because equal fat mass does not make two ingredients identical.
Use the two product percentages you intend to compare
Enter the original ingredient mass, its fat percentage and the replacement product’s fat percentage. The percentages are inputs, not live product data or a brand recommendation.
Check the basis of the product information you use. A fat mass per 100 g corresponds to a mass percentage; do not substitute a serving quantity without converting its basis.
The 100 g example produces an 80 g replacement
For 100 g original product at 80% fat and a replacement at 100% fat, the checked result is 80 g replacement. Both quantities supply 80 g fat.
- Original nonfat material: 20 g.
- Replacement nonfat material: 0 g.
- Original minus replacement nonfat: 20 g.
The formula is replacement mass = original mass × original fat percentage ÷ replacement fat percentage.
Nonfat does not automatically mean water
The 20 g difference is nonfat material. The calculator does not divide it into water, milk solids or any other components. Adding 20 g water is therefore not a recipe instruction derived from this result.
The same limitation applies when comparing butter, ghee, oil or other products. Entered percentages describe the arithmetic; ingredient behaviour remains outside the tool.
Check the role of the ingredient in your formula
This result cannot determine how a replacement affects texture, mixing or the finished product. It is useful as one comparison in a recipe development worksheet, not as permission to replace any fat with any other fat.
If your bread or naan formula uses a fat or oil percentage, Bread Dough Batch Calculator and Naan Dough Calculator allocate the product mass entered in that formula. They do not automatically apply this equal fat conversion.
Cost comparisons should use the actual replacement mass and your own quote. Recipe Cost Calculator can show the proportional usage cost, while a pack purchase remains a separate whole pack amount.
Save both product percentages with the output. A bare instruction to “use 80 g” hides the composition assumptions that produced it and can be misleading when either product changes.