Before you quote extra work
Price the change before doing the work.
Use the original project's price and estimated hours to calculate an hourly equivalent. Apply that equivalent to the extra effort, add only a buffer you can explain, state the schedule impact, and wait for written approval.
The result is a planning starting point—not a market rate, legal interpretation, or promise that a client will approve or pay it.
Free planning tool
Start with your own project economics.
Enter the original project numbers and the extra effort you expect. Nothing is uploaded or saved.
Planning starting point
Add a positive project price, original hour estimate, and extra hour estimate to see a starting point.
Four-line approval request
This request is outside the agreed scope. I can add it for [price]. It will add [schedule impact] to the schedule. Please approve the price and timing in writing before I begin.
This calculator is an educational planning aid. It does not set a fair price, interpret a contract, include taxes or platform fees, or guarantee approval or payment. Check the request against the actual agreement and choose the final amount yourself.
Transparent method
See exactly where the number comes from.
First, divide the original fixed price by the original estimated hours. That produces an hourly equivalent for this project—not a universal hourly rate. Multiply it by the extra work estimate, then apply the optional percentage only when additional coordination, uncertainty, or risk is genuinely present.
This method preserves the economics of the original estimate. It cannot tell you whether that estimate was correct, whether the request is already included, or whether another pricing method better fits the change.
Before sending
Check the boundary, not just the arithmetic.
- Compare the request with the named deliverables and revision limit.
- Clarify any missing acceptance condition or dependency.
- Include review, testing, handoff, and schedule disruption in your estimate.
- Replace the template wording with facts from the actual agreement.
- Wait for explicit written approval before starting the extra work.
Continue the workflow