I'm wiring a unattached residential garage with a 100a sub-panel. In the past I've charge per opening plus a % of profit added on. I've also figuerd about how long the job would take at about $45 an hour plus materials. Any other better ways to estimate a residential job like this?

Adding to the previous post.. I would charge about $20 an hour also for helpers on the hourly.

I say your on the right track there. However, depending where you are, your labor rate might be a bit low.

It might help to know what your competition charges, and work from there.

I'm in the Phoenix Arizona area. Your probably right, I need to raise my rates, very busy here.
Whats the going rate in other places?

I just went to $65 per hour per man...

Charge the same rate for the helper.

shortcircuit

On some smaller jobs you might figure it by the day. Per opening works better if you have at least a few full days of work. The idea is:

If it only takes you 5-6 hours to rough do you have somewhere elce near by to make use of the 2 hours. Also the trip factor. Do you need to go back after drywall or sidding? More trips adds to the travel, set up, and clean up time.

Also if you estomate by the day you may give yourself more time if things don't go well. I allways figure more time then I think. I think it's an easy mistake to say "that wont take long".

Labor rate sounds low. You should try one of those online excel labor rate calculators. I don't have the address now. If your busy charge more.

Don't forget material mark up (your in business to make $ not a free shopper for customer electrical needs).

Tom

Very good points, I need to raise my prices.
Doing a remodel now and have to charge Time and materials. Doing $45 an hour for me and $45 for my one helper, I already told the customer that. But will change for the future.