Trust & methodology

Sources & Verification

How changing retailer rules and consumer guidance are sourced, dated and reviewed.

Current launch sources

NIST SP 1181 — Unit Pricing Guide, 2025 EditionNational Institute of Standards and Technology · verified 2026-08-09

Official U.S. best-practice guide for unit pricing; updated May 20, 2026.

Uniform Unit Pricing: Tools for Consumers to Fight ShrinkflationNational Institute of Standards and Technology · verified 2026-08-09

Official consumer explanation of unit pricing and shrinkflation.

Online Shopping — Consumer AdviceFederal Trade Commission · verified 2026-08-09

FTC advises comparison shoppers to consider total cost including shipping, handling, delivery, taxes and other fees.

Subscribe & SaveAmazon Selling Partners · verified 2026-08-09

Current Amazon material states eligible subscribers can save up to 15%, depending on the discount tier.