He said the estimate was based on calculations the Cabinet Office made using various data.
The minister also said that cheaper oil would also likely to bring down overall prices in Japan. Weaker consumer demand and falling oil prices pose a challenge to the government’s efforts to lift prices across the economy trying to defeat deflation.
Since June 2014, oil prices have fallen by more than 40 percent and now stand at about $50 a barrel.
During a meeting in November, the Organization of Petroleum Exporting Countries (OPEC) decided not to change the levels of oil output, triggering a further drop in global oil prices.