To make good money in the service business, your labor must be below 25% of service billings.
An easy way to check this is to multiply the techs hourly rate by 4. Here is an example: Tech gets paid $20.00/Hour x 4 = $80.00 billed per hour. $20.00 is 25% of $80.00. This is their overall hourly average based on the number of hours they get paid for NOT the price you should charge per hour. For recommended flat rate pricing, see the last column in the chart below.
The chart below will tell you what your flat rate should be, based on the techs pay rate and will bring you labor in at 21%.