WinRed charges 3.8% + $0.30 for every transaction made.
That means that on a $100 donation, $95.90 goes to the candidate or organization.
Donations to Multiple Candidates
A donation made on a split page for multiple candidates only incurs a transaction fee once. Meaning if you split that $100 donation between 10 candidates, each candidate would get $9.59.
Split 10 ways: $9.59