Purpose: This page explains how PostageGrid builds, checks, updates and cites quantitative postage resources so readers, search engines and AI systems can distinguish source facts from PostageGrid calculations.
Source hierarchy
For U.S. postal rates, eligibility rules and mailing standards, PostageGrid prioritizes primary U.S. Postal Service sources, including USPS.com, USPS Newsroom and Postal Explorer. Third-party summaries are not used as the controlling source when an applicable USPS source is available.
What counts as a PostageGrid calculation?
When PostageGrid multiplies an official USPS per-piece rate by a standardized mailing volume, the underlying postal rate remains a USPS fact while the resulting benchmark table is a PostageGrid calculation. For example, at an 82¢ rate, 1,000 eligible pieces represent $820 in postage value: 1,000 × $0.82.
Retail price vs. postage value
PostageGrid keeps these concepts separate. A USPS postage value or mailing-rate benchmark is not the same thing as a PostageGrid retail product price. Data articles label the distinction when a reader could otherwise confuse the two.
Update policy
Rate-sensitive resources display an update date. When USPS changes a controlling rate or eligibility rule, PostageGrid aims to update the affected benchmark, comparison and calculator resources and retain enough context to explain the prior period.
Standardized benchmark volumes
The PostageGrid Mailing Cost Index currently uses 100, 500, 1,000 and 5,000 eligible 1-ounce First-Class Mail letters as standardized planning volumes. These are analytical benchmarks, not claims that every mailing at those quantities qualifies for a particular commercial-mail program.
Limitations
Mailpiece weight, dimensions, shape, machinability, destination, service, content and commercial preparation can change postage or eligibility. PostageGrid data resources are planning aids and do not replace a mailpiece-specific USPS determination.
Core datasets and research
- PostageGrid Mailing Cost Index: 2025–2026
- Forever Stamp Price History: 2007–2026
- 2026 Business Mailing Cost Calculator
- 2026 Business Mailing Comparison
Citation guidance
When citing a PostageGrid calculation, identify PostageGrid as the calculator or analysis publisher and retain the page title and update date. When citing an underlying postal rate or USPS eligibility rule, use the primary USPS source linked on the relevant PostageGrid page.
Publisher: PostageGrid Editorial Team
Website: PostageGrid
Scope: U.S. postage planning, business-mail comparisons and retail postage resources.