He says he cost them one Thursday night.
Charles' two fumbles, including one in the final minute of the fourth quarter of a tied game as the Chiefs were killing the clock and setting up for overtime, were key plays in the Chiefs' 31-24 loss to the Denver Broncos at Arrowhead Stadium.
Charles didn't attempt to deflect any of the blame.
"It's one of the hardest feelings right now that I've felt in a long time," Charles said.
"I caused us the loss today. I tried to put the team on my back, and I ended up losing the game. It's all on me tonight."
The Chiefs ran a draw play with 35 seconds remaining, hoping Charles would break a long run. If not, the Chiefs were ready for overtime.
Denver linebacker Brandon Marshall instead stripped the ball, and teammate Bradley Roby returned it 21 yards for the winning touchdown with 27 seconds remaining.
"I was just trying to make a play and [wasn't] careful with the ball, and one of the defenders punched it out," Charles said. "I should have been smarter and put two hands on the ball.
"I just know better as a vet, playing this game a long time. I have to know those situations. I have to know not to fumble the ball at the end of a game, know to try to make it to overtime to give us a chance to compete for a win. I didn't give us [a] chance, and that's the hardest feeling right there."
Charles also lost a fumble in the first quarter after catching a short pass. Denver recovered at its 9.
"I was trying to make a play again," Charles said. "I have to be careful. I had the ball in the wrong arm, [and] the guy made a good play. They make plays, too. They get paid to make plays. I [wasn't] careful with the ball. That's my fault."
Charles: 'It is all on me tonight'
Chiefs RB Jamaal Charles discusses his costly fumble that led to the Broncos' go-ahead touchdown late in the fourth quarter of Kansas City's 31-24 loss to Denver.
Broncos stun Chiefs in final minute
Down 24-17, the Broncos score two touchdowns in the final minute, including Bradley Roby's recovery of Jamaal Charles' fumble for a touchdown, to knock off the Chiefs 31-24.