There are three main ways of developing an estimate of the evaluation cost when budgeting for the whole program.
1. Percentage of the cost of the program
Depending on the size of the program, some organizations suggest using a rule of thumb of allocating 5-10% of the project cost to funding an external evaluation. However, if the project budget is very large, existing data is already very good, and a comprehensive evaluation is not needed, the percentage funding needed will be significantly less. Conversely, for a small, innovative project where the evaluation is intended to do a lot of work documenting and supporting the innovation, and learning lessons for the future, the budget required could be significantly more – 20%-40%.
2. Estimating days needed
The following example from the United Nations Office on Drugs and Crime (UNODC) shows an estimate for days needed for each stage of a simple end of project evaluation involving 2 evaluators – an international consultant and a national consultant. In this example, it is assumed that the national evaluator will be working under the supervision of the international evaluator. This is not always the case.
3. Ballpark figures for similar types of evaluations
A Randomized Controlled Trial which largely draws on existing data – $50,000 to $300,000, (Based on paper from the Coalition for Evidence-Based Policy).
Checklist for evaluation budgets – this checklist, developed by Jerry Horn as part of the Western Michigan University Evaluation Checklists project, provides useful prompts about items that might need to be included and how they might be estimated.
Blank evaluation budget from CARE Uganda listing many items that might be included.
Evaluation budget templates in Excel from the National Institutes of Health with different versions for different situations in terms of labor costing (with or without fringe benefits) and travel.
Identify what resources are available for the evaluation and what will be needed - this page, a sub-step from Steps in planning and managing an evaluation, looks at the resources needed for an evaluation and lists five ways to estimate the budget of an external evaluation.