This chapter presents the levelised cost of electricity (LCOE) for new nuclear power. Section 4.1 redefines levelised cost, assuming that the costs are constant in each year of plant operation. Section 4.2 calculates nuclear fuel costs and probability distributions. Section 4.3 calculates operations and maintenance (O&M) costs and probability distributions. Section 4.4 presents first-of-a-kind (FOAK) and nth-of-a-kind (NOAK) deterministic levelised cost estimates for new nuclear by combining the results of Chapter 3 with Sections 4.2–4.3. Appendix 4A discusses used nuclear fuel recycling, extending the discussion in Section 4.2. To determine levelised costs, this chapter uses a range of costs of capital between 3% and 12% (as discussed in Chapter 2, Section 2.4). Chapter 5 calculates, simulates and compares probability distributions of levelised costs of new nuclear, combined-cycle natural gas turbines and pollution-controlled coal.