to some degree that depends on the distance you need to drive but I charge at least 50 % above my regular hourly rate. Ultimately, you really have to allocate 2 hours of your time for 1 hour of training.
You can do it two ways. you can charge for the entire time it takes you to drive and train or just charge a little extra for gas. I charge $60 to go somewhere and train and $50 to train at my gym. I don’t really ever get anybody that wants me to go their house anymore so I don’t make it a big deal. If it takes you 30 min each way then that is time you could be scheduling another client. I think it fair to charge for the time it takes you to get there and back.
All I do is mobile training. I go to my client’s location to train them, so my fees already include all of those costs and expenses associated with the traveling time. You will get many different answers here, so you will need to decide what your time is worth when going to client’s homes. You can charge them an extra 10%, 20% or more depending on those extra expenses you might have (parking or toll fees), extra gas (mileage) or by the minutes it takes you to go to the location (extra $$ for every 10,15, 20 or 30 minutes) on top of your regular rate.
I hope this helps.