The new tax rates, that came into effect on Wednesday, would further curb rice imports, especially from neighbouring India, which emerged as the biggest supplier to the South Asian country in 2017, after floods destroyed its crop.
The move would help protect farmers' interests as growers are being compelled to sell their rice at lower rates than the production costs, a food ministry official said.
Local rice prices have fallen to their lowest in three years due to ample supply from last year's crop and forecasts of record output.
Bangladesh re-imposed a previous import duty of 28pc in June after reducing it in two phases in 2017, to 2pc, as local rice prices climbed to a record high.
Domestic stocks have since greatly improved on the back of massive imports and good crops.
Despite a hefty import duty, private traders imported more than 330,000 tonnes of rice in the July-April period, the government data showed.