This paper investigates different methodologies for computing effective corporate tax rates. All methodologies present strengths and shortcomings, as well as different rankings of countries. One reason lies in the fact that different methodologies measure different things. This paper also computes effective corporate taxation for eleven European countries, the US, and Japan using financial statements of companies. It indicates that there are large differences between statutory and effective taxation, as well as between countries for different sectors and companies' sizes. Finally, it suggests that effective corporate taxation is sensitive to the business cycle.