The importance of the research and its distinction from the previous research lies not in dealing with the ability of fiscal policy tools, i.e., government spending and taxes, to bridge the output gap, but also in it calculating the required amount of spending and taxes to close the output gap, as long as there is some amount of spending and taxes more or less than that. The required limit may cause damage to the economy, i.e., the outbreak of inflation or recession. Consequently, this research is considered as a guide for policy makers to know the required change in government spending and taxes accurately to avoid economic problems and achieve economic stability. The output gap, whether positive or negative, is a non-positive case, as long as it generates damage to the economy, represented by inflation or recession. Fiscal policy, with its various tools, may be unable to close the output gap due to the deficiency in the performance of these tools, which requires monetary policy assistance. The research problem is also indicated that when there is a recession, an expansionary fiscal policy (increasing government spending and reducing taxes) is necessary. But when there is inflation, a contractionary policy should be followed (reducing spending and raising taxes). However, the problem is that if the exact amount of government spending and taxes changes is not determined, severe damages are generated, such as an inaccurate drug dose. This is not to mention the slowdowns or lags in the transmission of the impact of fiscal policy measures to the targeted variables. The research chose a time frame that extended from 2000 to 2020. As for the spatial aspect, it was represented in a sample from different continents in order to make a successful comparison between them. These countries are the United States, Germany, Japan and Iraq. The research found that in all countries of the research sample, the government spending gap was positive, which means that it is at a level higher than the level required to bridge the output gap, perhaps because there are other items for spending on it other than closing the output gap, as is the case for the tax gap, which exceeded the required limit to eliminate Output gap, excluding Iraq.