Clients usually prefer a fixed price, but a fixed price is only safe if it covers the time the project really takes. This estimator starts from your hours and rate, adds a buffer for the overruns almost every project has, and tells you what deposit to ask for.
How it works
Multiply your estimated hours by your hourly rate. That is the price if everything goes exactly to plan.
Add a buffer as a percentage of that amount. It covers extra revision rounds, meetings, feedback delays and the parts of the job that turn out harder than expected. Add any project expenses on top.
A deposit, often 30 to 50% for new clients, reduces your risk if the project stalls, and shows the client is committed before you start.
A worked example
40 hours at $83 an hour is $3,320. A 20% buffer adds $664, for a quote of $3,984, which covers 48 hours of work. A 50% deposit is $1,992.
Questions people ask
Should I show the buffer to the client?
Usually not as a separate line. Quote one project price, and describe what it includes, such as two rounds of revisions. The buffer is how you make sure that price covers the real work.
How big should the buffer be?
Look at your past projects: how far over your estimate did they go? If you have no history yet, 20% is a reasonable start. Increase it for unclear briefs, new types of work or clients who give a lot of feedback.
What if the project goes beyond the buffer?
Agree in writing what is included before you start. Anything outside that, such as new features or extra revision rounds, can be quoted separately as a change request.