About

Precise weight conversion is vital for e-commerce sellers navigating postal rates and parents tracking newborn growth. A fraction of an ounce can bump a package into a higher shipping class, doubling the cost. This tool converts metric and imperial weights into three useful formats: decimal ounces, decimal pounds, and the human-friendly "Pounds + Ounces" mix.

It specifically highlights common Postal Thresholds (e.g., the 13 oz / 15.99 oz limit for USPS First Class), acting as a quick check for shipping optimization.

Formulas

The core conversion relies on the definition of the international avoirdupois ounce:

1 oz = 28.349523125 g

To calculate the mixed format (lb + oz):

lb = floor(TotalOz ÷ 16)

RemOz = TotalOz % 16

Reference Data

Input (g)	Ounces (oz)	Mixed (lb oz)	Postal Context
28.35	1.0	0 lb 1 oz	Letter Base Rate
100	3.53	0 lb 3.5 oz	Large Letter
368.5	13.0	0 lb 13 oz	USPS First Class Retail Limit
453.6	16.0	1 lb 0 oz	1 Pound Standard
1000	35.27	2 lb 3.3 oz	1 Kilogram

Frequently Asked Questions

For retail (Post Office) purchase, packages must be under 13 oz. For Commercial Base (online labels), the limit extends to 15.99 oz. Crossing this pushes the package to Priority Mail, which is significantly more expensive.

Mixed units (e.g., 7 lbs 4 oz) are the standard for expressing body weight (babies) and cooking in the UK/US. Decimal pounds (7.25 lbs) are often used in shipping software.

No. This tool uses "Avoirdupois" ounces (everyday weight). Precious metals use "Troy" ounces (~31.1g). Do not use this tool for gold or silver trading.