I've recently quoted a client on a project for 16 hours of effort. I've told him that I can deliver the work in 3 weeks time.
However, he took the 16 hours of effort literally and expected me to deliver the next day since 16 hours of effort is what I've quoted.
Well, clearly, that 16 hours is just a unit for estimating the amount of effort required and hence the fee, but he couldn't seem to understand how I could charge him 16 hours on one hand and yet require 3 weeks of time to deliver the work.
I've used an hourly rate with this client because I believe he might have additional changes and an hourly rate allows me to justify any extra fees required for those changes.
How should I explain to the client that the 16-hour effort estimation doesn't mean precisely I will spend 16 hours to complete the work?
Or is the client totally right to think that I only need 16 hours for the work when I provide that estimation? If so, how does an hourly rate even work because the cost will surely blow up into a 5-digit figure if I really count every single hour I spent on it.