Data Sources

Where our caffeine values come from

Every caffeine value in the Caffeine Math database is sourced from one of the following authoritative references. We never invent or estimate caffeine content — if we cannot verify a value, we mark it as a TODO and do not publish it until verified.

1. USDA FoodData Central

The U.S. Department of Agriculture's FoodData Central is the primary source for caffeine content of foods and beverages. It is the standard reference used by researchers and health professionals in the United States. We use the values published in the "Foundation Foods" and "SR Legacy" datasets.

Visit FoodData Central →

2. U.S. Food and Drug Administration (FDA)

The FDA provides guidance on safe caffeine intake levels. The 400 mg/day limit for healthy adults comes from the FDA's consumer guidance. We also reference FDA regulations on caffeine labeling for energy drinks and dietary supplements.

3. European Food Safety Authority (EFSA)

EFSA's 2015 Scientific Opinion on caffeine safety provides the 200 mg/day single-dose limit and the 400 mg/day total limit for healthy adults. We cross-reference FDA and EFSA guidance.

4. American College of Obstetricians and Gynecologists (ACOG)

ACOG's Committee Opinion on moderate caffeine consumption during pregnancy provides the 200 mg/day limit for pregnant women.

5. American Academy of Pediatrics (AAP)

The AAP recommends that children under 12 avoid caffeine entirely and adolescents (12–18) limit intake to 100 mg/day.

6. Manufacturer labels

For branded products (Starbucks, Red Bull, Monster, Bang, Celsius, etc.), we use the caffeine values published by the manufacturer on the product label or official website. When a brand reformulates, we update our database within 30 days of becoming aware of the change.

TODO: Bang Energy caffeine content is currently listed as 300 mg per 16 oz. Some sources report it may have been reduced to 250 mg. We are verifying with the manufacturer and will update once confirmed.

How often we update

• Database: Reviewed monthly for brand reformulations
• Safety limits: Updated when FDA, EFSA, ACOG, or AAP publish new guidance
• New beverages: Added as new products enter the market, verified from labels

How to report an error

If you find an incorrect caffeine value or outdated information, use the "Report an error" link on any drink or guide page, or visit our contact page. We respond to all data correction reports within 7 days.

Limitations

• Caffeine content can vary by 20% or more depending on brew method, bean variety, roast level, and serving size
• Values are typical averages, not exact measurements of a specific cup
• Energy drink caffeine can vary batch-to-batch by ~10%
• We do not test beverages in a laboratory — we rely on published data