There must be 40 million by now, you should be glad that you live in Poland:)
1% of the population: Czech Republic, Estonia, Finland, Hungary, Iceland, Ireland, Latvia, Lithuania, Moldova, Poland, Portugal, Romania, Slovakia. 1%-2% of the population: Belarus, Croatia, Italy, Monaco, Ukraine. 2%-4% of the population: Andorra, Denmark, Luxembourg, Norway, Serbia, Slovenia, Spain. 4%-5% of the population: Germany, Greece, Liechtenstein, Switzerland, United Kingdom. 5%-10% of the population: Austria, Belgium, France, Netherlands, Sweden. 10%-20% of the population: Bulgaria, Cyprus, Montenegro, Russia. 30%-50% of the population: Bosnia Herzegovina, Macedonia, Albania. 70%-90% of the population: Kosovo. 90%-100% of the population: Turkey.
So within the European Union, we have an estimated number of 16-20 million Muslims and about 813-820 million Europeans. If we're going to count Turkey, Russia and a few other countries, then we would have an estimated number of about 53 million Muslims. Keep in mind that no one has the exact figures, but looking at various sources, I'd say that these estimations are pretty close to reality.