Hourly to Fixed-Fee Project Calculator
Convert an hourly rate and estimated hours into a fixed project fee, with a risk buffer for scope creep and the effective rate you would actually earn.
How it works
Buffered hours = hours × (1 + buffer%) · Fee = buffered hours × rate × (1 − discount%) · Effective rate = fee ÷ actual hours worked
A fixed fee shifts the risk of overruns from the client to you, so pricing it means padding your honest hour estimate with a buffer. If the job comes in on estimate, your effective rate beats your hourly rate; if it runs to the full buffered hours, you land back near your base rate. The two effective-rate figures show the best and worst outcomes so you can judge whether the flat price is worth the certainty it buys.
Worked example
At $90/h with a 40-hour estimate and a 20% buffer, you price 48 hours: 48 × $90 = $4,320. Finish in the estimated 40 hours and you effectively earned $108/h; use all 48 and you earned $90/h.
Frequently asked questions
Why offer a fixed fee at all?
Clients often prefer a known total to an open-ended hourly meter, and it removes friction over timesheets. The trade-off is that you absorb overrun risk, which the buffer is meant to cover.
How big should the buffer be?
Match it to how well the scope is defined. Tight, familiar work might need only 10–15%; vague or novel projects can justify 25% or more. The looser the scope, the larger the cushion.
What if the project runs past the buffered hours?
Then your effective rate drops below your hourly rate — the risk you accepted. A clear written scope and a change-order clause let you re-price work that falls outside the original agreement.
Related calculators
Educational estimate, not financial advice.