The amount Americans owe on student loans is far higher than earlier estimates and could lead some consumers to postpone buying homes, potentially slowing the housing recovery, U.S. officials said Wednesday.

Total student debt outstanding appears to have surpassed $1 trillion late last year, said officials at the Consumer Financial Protection Bureau, a federal agency created in the wake of the financial crisis. That would be roughly 16% higher than an estimate earlier this year by the Federal Reserve Bank of New York.

The...