WASHINGTON — The House Republican tax bill is a clear windfall for corporate America and a roll of the dice for the middle-class families that President Trump promised would be the centerpiece of his economic agenda.

Early projections suggest the bill would cut taxes for an average middle-class family. But the typical cut could be relatively modest, compared with the benefits for businesses and high earners. More important, the myriad changes in the code would actually raise taxes on nearly 13 million tax filers who earn $100,000 a year or less, according to preliminary calculations using the open-source economic modeling software TaxBrain.

Those changes also include limits on, or the elimination of, what might be called tax breaks for middle-class aspirers. The bill would no longer allow Americans to deduct interest on student loans they took out to attend college. It would limit mortgage interest deductions to $500,000 on newly purchased homes, a provision that would hit middle-class teachers or office workers looking to buy starter houses in high-priced, economically vibrant areas such as New York City and Silicon Valley.

One of the bill’s biggest lifts to working families would vanish after five years — though Republicans would certainly push to extend it — and another would be diluted by the bill’s changes to how the tax code calculates inflation.