How much can I make per day online

This is a loaded question and impossible to answer in a short thread.

You should first think about what it is you are interested in, do you have a hobby. It is often best to start a business on the internet based on a hobby or interest as you know something about the subject all ready and you have an interest in that subject so it will make earning a living in the field easier.

It's not really how much you can make in a day. You have to set short term and long term goals to make money online.

Also you have to decide what you would like to do because there are many ways to make money online.

There are various factors to look at to determine how much money you can make a day so just don't look at it on a daily basis.

It Depends on the industry and type of job you're doing... there are some affiliate programs that who are paying up to $200 per sale so with good traffic and good website is possible to get a sale per day or two.

If you are going to use Get-Paid-To programs, which I don't advise, then it will take you a lot of time before you can earn decent amount of money, unless you know a lot of people online who can sign up under you and earn through their referral programs.

If you are going to use blogging to earn money from ads like Google AdSense or Text-Link-Ads, depending on your blog's niche, how well you write and how you promote your blog, it will also take a few months before you can earn decent amount of money.