Angela Cupit pleaded guilty to conspiracy to possess, -with the intent to distribute, 50 grams or more of methamphetamine, in violation of 21 U.S.C. § 846. She was sentenced, inter alia, to 360 months’ imprisonment.

For the one issue presented on appeal, Cupit contends the district court erred in finding she was accountable for the total amount of drugs received during the conspiracy, the marijuana equivalent of 238,-937.6 kilograms.

Although post-Booker, the Guidelines are advisory only, and a properly preserved objection to an ultimate sentence is reviewed for reasonableness under an abuse-of-discretion standard, the district court must still properly calculate the Guideline-sentencing range for use in deciding on the sentence to impose. Gall v. United States, 552 U.S. 38, 48-51, 128 S.Ct. 586, 169 L.Ed.2d 445 (2007). In that respect, for issues preserved in district court, its application of the Guidelines is reviewed de novo; its factual findings, only for clear error. E.g., United States v. Cisneros-Gutierrez, 517 F.3d 751, 764 (5th Cir. 2008).

In initially objecting to the drug quantity the presentence investigation report (PSR) attributed to her, Cupit maintained: although her co-defendant supplied her with methamphetamine, she was not involved in his distribution to others; therefore, she should only be accountable for amounts she personally distributed. At sentencing, however, Cupit withdrew her objections to the PSR.

“Forfeiture is the failure to make the timely assertion of a right; waiver is the intentional relinquishment of a known right.” United States v. Arviso-Mata, 442 F.3d 382, 384 (5th Cir. 2006). Although forfeited errors are reviewed for plain error; waived errors are unreviewable. Id. Withdrawing an objection at sentencing constitutes a waiver. See United States v. Conn, 657 F.3d 280, 286 (5th Cir. 2011). Because Cupit withdrew her objection to the drug-quantity determination, she has waived her sole issue on appeal. See, e.g., *274 United States v. Medrano, 452 Fed.Appx. 469, 470 (5th Cir. 2011) (unpublished).

AFFIRMED.