Investment Performance Calculator is an easy-to-use financial utility for calculating time- and dollar-weighted rates of return on any investment. The computations performed by Investment Performance Calculator are compliant with the performance presentation standards set by the Association for Investment Management and Research (AIMR). Performance numbers are calculated using the Modified Dietz formula, with those greater than one year being automatically annualized. You can view a detailed log showing what numbers were used with the Modified Dietz formula for each compounding period (monthly). You can also group your investments in portfolios, import historical pricing data from CSV files, and export your data.