Given fractional banking and the multiplier effect, for every dollar in circulation, how many dollars in spendable money exist? The fractional banking system, in a nutshell, allows banks to invest the money deposited in them, and then for whoever ends up with that invested money to deposit the money back into the bank, which can then reinvest it and so on. For example, let's say Mike puts \$1000 into a bank. The bank might invest \$800 of those dollars into a factory, which then pays the \$800 to its workers that themselves deposit their \$800 into the bank. So while Mike's bank account balance still reads \$1000, the workers' bank accounts include \$800 of those same dollars that have been paid out on loan from the bank, meaning the bank has effectively turned Mike's \$1000 into \$1800, and can loan out that same \$800 to triple dip, quadruple dip, and so on ad infinitum.

In practice, in the world and the United States, how many spendable dollars are created for each actual dollar in circulation, M0 to M1?
The initial statements about fractional reserve banking are not a question. The simplified example you give does not reflect the complexity of bank lending. The article "Money Creation in the Modern Economy," by Michael McLeay, Amar Radia and Ryland Thomas of the Bank of England link to paper is one place to start to get a more realistic discussion of money creation.


  In practice, in the world and the United States, how many spendable
  dollars are created for each actual dollar in circulation, M0 to M1?


For the United States, these data are available at FRED, a service run by the St. Louis Fed. link to FRED

The relationship changes over time; the policy of quantitative easing greatly affected money supply numbers, and the relationship between them.

If you are interested in multiple countries, you will probably need to track down data from central banks or statistical agencies, or you may be able to find an aggregate source. I am unaware of any free data suppliers that cover money supply data.