The article introduces a new way to measure investment returns called Aggregate Return on Investment (AROI). AROI is based on the ratio of net cash flow to capital invested and is independent of market rates. It helps in making decisions about accepting or rejecting projects and ranking them. AROI uses a comprehensive cost of capital that considers all relevant factors. This approach breaks down project value into excess-rate and excess-capital components. The traditional Internal Rate of Return (IRR) is a special case of AROI, but AROI provides a clearer understanding of returns and costs.