The Cumbrians, playing infront of their biggest crowd of the season, took the lead seven minutes in through Brendan McGill.
It looked like they would take their fight against relegation to the final day when defender Lee Andrews pulled off a headed goaline clearance.
But from the resulting corner Kayode Odejayi headed home to silence the home support and condemn them to Conference football next season.
Their final game in the Football League will be at newcly-crowned champions Doncaster next week.
Had Carlisle held on for the win they would have been two points behind Scunthorpe with one game to play, but the draw leaves them unable to catch United.
York City's 2-1 home defeat at the hands of Leyton Orient confirmed their relegation.