About & Methodology

Who publishes this data

CalRay is an AI-powered calorie and nutrition tracking app for iOS. This site (calray.app) is both the marketing site for the app and a free, public nutrition reference covering 363 individual foods. It's maintained by the CalRay team as a companion resource to the app — the goal is to make USDA-grade nutrition data easier to look up than the raw government database.

Where the numbers come from

Every food's base nutrition values (calories, protein, carbs, fat, fiber, sugar, sodium, vitamins, and minerals) come from the USDA FoodData Central Foundation Foods database — the same public dataset used by dietitians and other nutrition apps. We do not use crowdsourced or user-submitted values for the core nutrition facts.

How calories are calculated

Where USDA reports a directly measured energy value (calorimetry), we use it as-is. For the small number of records where USDA's own dataset doesn't include a measured energy value, we calculate it from the reported macronutrients using the standard Atwater formula: 4 kcal/g protein + 4 kcal/g carbohydrate + 9 kcal/g fat. Every food's calorie value is automatically checked against this formula before publishing — if a value doesn't reasonably reconcile with its macros, or a food is missing the data needed to calculate it at all, that page isn't published rather than shipping a wrong or placeholder number.

Known limitations

Database size. We currently cover 363 whole foods plus a growing set of restaurant menu items — a fraction of commercial databases with 100,000+ branded products. We're expanding this over time; if a food you're looking for isn't listed yet, that's why.
Serving sizes. Most foods show USDA-standard serving sizes (grams, common household measures) alongside the per-100g value. Not every food has a USDA-reported serving size yet.
Preparation method matters. Nutrition values differ between raw, cooked, canned, and other preparations of the same food — we list these as separate entries rather than averaging them, which is why you may see, for example, both "raw" and "dried" versions of the same food.

Update cadence

USDA nutrition data is refreshed against the latest FoodData Central release on a quarterly basis. Editorial content (food-science context, comparisons, guides) is reviewed and expanded on an ongoing basis; each food page reflects when its nutrition data was last synced with USDA.

Corrections

Found a number that looks wrong? Email data@calray.app with the food page URL and we'll check it against the source USDA record.