The visible edit is often only one part of a website change. A new widget may require clarifying the client's settings, checking the layout, testing the integration and explaining the result. Estimate those tasks before you choose a fixed price.
Break the request into four groups: clarification and design, implementation, testing, and communication or handoff. Include setup time and review work when they are actually needed. If you cannot describe what “done” means, clarify the request first.
Use an internal rate that fits your business costs and realistic billable capacity. Multiplying hours by a rate is a planning method; it does not guarantee that a client will pay the amount or that the work will be profitable. Compare actual hours against estimates after completed projects.
Add contingency for specific uncertainty. A known integration you have used repeatedly may need less than an unfamiliar service with incomplete documentation. If uncertainty is too high, define a small discovery task with its own deliverable instead of pretending the implementation estimate is precise.
The simple calculation is total task hours × internal hourly rate × (1 + contingency percentage / 100) + direct costs. For an illustrative five-hour request at USD 80/hour with 20% contingency and no direct costs, the estimate is USD 480. State taxes separately as applicable.
Calendar impact is a separate judgment. Five hours of work does not automatically mean a one-day delay. The change may depend on a client review window, a third-party account or your next available slot. Check those before promising a revised launch date.
Give the client a decision-ready quote: included work, completion criteria, boundaries, fee, required inputs and schedule impact. Offer the option to defer or retain the existing scope. If they want a substitution, agree explicitly which deliverable comes out.
The Revision Desk quote builder calculates the estimate and formats a printable client-facing worksheet. You still choose the assumptions and confirm the realistic schedule.