USPS Dimensional Weight Calculator
Estimate USPS dimensional weight with the current tracked divisor and see the July 12, 2026 divisor change noted in the calculator guidance.
Divisors auto-fill from tracked public carrier rules and can be overwritten. USPS current dimensional divisor is 166 for qualifying packages over one cubic foot. This rule is scheduled to change on July 12, 2026.
Your calculation: 16 x 12 x 10 / 166 = 11.57 lb.
USPS rule timing
ShipCalc tracks USPS divisor 166 as the current rule before July 12, 2026 for qualifying parcels over one cubic foot.
The future USPS rule tracked in the data source page uses divisor 139 from July 12, 2026 for relevant products, with dimensions rounded up to whole inches.
What USPS divisor is active now?
As of June 25, 2026, ShipCalc keeps USPS divisor 166 active for qualifying packages until July 11, 2026.
What changes on July 12, 2026?
USPS published a future dimensional pricing change using divisor 139 for relevant products from July 12, 2026. ShipCalc tracks that future rule separately.