Nigeria introduced a new health fund in 2014, but there was uncertainty about the health benefit package that could be purchased using the new fund. Hence, a simple toolkit for estimating the financial feasibility of the new fund called the Basic Health Care Provision Fund in Nigeria was developed. The toolkit was developed following a scoping review of literature and brainstorming with experts, and pretesting of the initial design was used to further refine the toolkit, which was thereafter used to assess the financial feasibility of the Basic Health Care Provision Fund. The toolkit is excel-based and includes methods for computing recurrent and capital costs, revenue analysis, unit costs of the benefit package, and financial projections based on different scenarios for revenue and costs of the different benefit packages. The toolkit was used to produce plausible financial feasibility estimates of using the Basic Health Care Provision Fund to cover a minimum health benefit package that focused on maternal and child health services. It itemizes the input and output variables of interest for a feasibility analysis when a maternal and child health intervention is used as an example and the process of data collection, analysis, and interpretation. The kit also showed the level of coverage at different revenue and cost projections and the funding gap that would be covered before universal access to maternal and child health services would be achieved. In conclusion, the toolkit can be used to examine different expenditure and revenue scenarios, allowing the users to adapt and apply the toolkit to different contexts and different assumptions.