This paper discusses four simple steps for producing angular-shaped fly ash aggregate. The process is quick and cost-effective and involves mixing, compaction, curing and crushing. The paper compares the engineering properties of the resulting aggregate with those of conventional stone aggregates. Previous processes for producing aggregates using fly ash have been developed but are very costly and time-consuming, limiting their use in civil engineering applications. After various trials, mixes of 96–98% class C fly ash with 2–4% binder and 85–88% class F fly ash with 12–15% binder were found suitable to produce lightweight fly ash aggregate with dense structures and angular shapes for better interlocking, excellent toughness, hardness and high durability. This fly ash aggregate meets the specifications of MORTH (2013) and IS 383 (2016) for road aggregate and structural concrete aggregate, respectively. Tests show that fly ash aggregate can be used in concrete work without compromising its strength, and the resulting concrete is lightweight. Finally, the financial analysis for setting up a pilot plant for manufacturing angular-shaped fly ash aggregate is presented, showing that the production cost of fly ash aggregate is significantly lower than that of natural stone aggregate.