At 4 expected owner hours × $30 plus $30 other costs, fixed cost is $150. A 25% margin implies a $200 flat quote. A $50-per-billable-hour rate over four hours also bills $200, but overruns change the hourly invoice.
Flat rate
Quote a defined outcome and include the labor you expect plus uncertainty you are willing to carry. State what triggers a change order.
Hourly
State the hourly billing unit, any minimum visit charge, and how materials and travel are handled. The customer may need an estimate or cap.
Compare on the same scope
Calculate the expected total cost under each method before deciding. Do not compare a flat project price with only the visible delivery hours.
When to use this method
Choose flat rate when the outcome and change boundary are clear enough to quote; choose an hourly structure when duration is the meaningful billable unit and the client accepts that uncertainty.
A mistake to avoid
Do not compare a flat price covering planning, travel, and materials with an hourly quote that counts only hands-on time.
What this does not tell you
These are calculation examples using stated assumptions. They are not national service rates, local quotes, tax advice, or a prediction of demand. Confirm your own scope, costs, fee basis, and any local requirements before sending a price.
Source and updates
The formulas and assumptions are explained in our methodology. This guide was prepared on 2026-11-06. If you find an error, send a correction.