Music collection agency Audiam has created a free payment calculator based on per streaming mechanical royalty rates supplied to them by Spotify. The rates are for the United States and only for mechanical royalties.
Mechanical royalty rates also vary month to month, based on how many total streams occur in Spotify in the US and how much money Spotify in the US has made each month. These royalties are paid to music publishers directly by Spotify and are not paid to TuneCore, CD Baby, DistroKid or any record label.
"If there are recordings of your music in Spotify in the US that have streamed, and you have not been paid these second separate mechanical royalties," says Audiam's Jeff Price, "Spotify has either not paid you in or Spotify did not get a license to your composition in the first place."
The rates for sound recordings and the rates in other countries also differ.
Calculate your earnings here.