Free Ad Spend Budget calculator with clear step-by-step results.
Back-solves the advertising budget you need from the revenue you want and the return on ad spend you can realistically hit, then adds management fees and fixed creative costs so the number you take to finance is the full cost of the channel rather than media alone.
Media spend
Media = revenue target / target ROAS
Total budget
Total = media + media x fee rate + creative budget
ROAS is revenue per dollar of spend. If every dollar returns four dollars, reaching $50,000 of revenue needs $50,000 / 4 = $12,500 of media.
Most agencies bill a percentage of media on top of it, which is how this is modelled. If your contract deducts the fee from a fixed budget instead, enter the fee as 0 and reduce the media figure yourself.