Estimate extra value from your services.
Clients buy outcomes, so the persuasive number is the value your work creates rather than the hours it took. Discounting the client's total gain by an honest attribution share keeps the claim credible — market conditions and their own team contributed too — and comparing the result with your fee gives the return they earned. A fee that is a small share of attributed value is both defensible and a signal you could charge more.
Attributed value and client ROI
Attributed value = client yearly gain x attribution/100; client ROI = (attributed value - fee) / fee x 100
Ask what would have happened without you. If the client would have captured part of the gain anyway, attribution is well below 100% — and a conservative figure survives scrutiny far better.
It converts an outcome into a rate you can compare with your hourly pricing, which usually reveals a large gap in favour of value-based fees.
It is a pricing signal. A fee in the low single-digit percentages of the value delivered suggests room to raise prices without threatening the client's return.