1,152 cubic inches ÷ 139 = 8.29, rounded up to 9 lb for UPS Daily Rates and FedEx. USPS bills actual weight because the box is not larger than 1 cubic foot.
How heavy does a 12x12x8 box need to be to avoid DIM charges?
With UPS and FedEx, anything packed under 9 lb is billed as 9 lb. Above that, you pay actual weight.