The formula for the annual return calculation from returns of shorter time periods, such as months or quarters, is not a simplistic one.
According to the methodology followed by the National Association of Real Estate Fiduciaries (NCREIF) the calculation of time-weighted annual/annualized returns from quarterly returns is carried out by chain linking quarterly rates of return. The assumption behind the chain linking formula is that within the estimated one-year period returns from each quarter are «reinvested» in the property in subsequent quarters up to the end of the one-year period. The return calculated in this way is referred to as compounded return because of the reinvestment assumption.