GF premium

The GF premium is the extra cost a household pays for the gluten-free version of a food, compared with the non-gluten-free version of the same food. The premium is the per-item difference, summed across the year. Gluten Hero is built around producing it cleanly.

The math is simple at the item level. A loaf of gluten-free bread at $7. The same household's usual non-gluten-free bread at $4. The premium on that loaf is $3. That number, summed across every item where both prices are known, is the household's annual GF premium.

The math is also conservative. Items where the household has not entered a regular price do not enter the premium calculation; they are tracked but excluded from the comparison until a regular price is added. Items flagged GF-Only (xanthan gum, certified GF oats, specialty mixes with no non-gluten-free counterpart) count their full price as a medical expense rather than a premium, per the Revenue Ruling 55-261 rule on special-diet costs. Sales on the gluten-free item never go negative; the per-item premium is clipped at zero (see excess cost).

The premium is what lands on the medical line of Schedule A, above the AGI floor, in a year when the household itemizes. It is also what the Insights tab on the Reports page surfaces in the GF-vs-regular cost-ratio card and the projected-annual card.

The cleaner the comparable basket, the sharper the premium. The more items the household logs with both prices, the closer the GF premium gets to the actual household cost of celiac.

For the full walkthrough of the concept and how to build the basket, read Building the gluten-free vs gluten control basket.