The principle in the New Testament is to give voluntarily to support the needs of others (Acts 2:45; Romans 15:25-27), support Christian workers (1 Corinthians 9:11-12; 1 Timothy 5:18), and expand Christian outreach (Philippians 4:15-16). No specific amount is ever commanded, and no percentage is suggested.
— Read on www.gotquestions.org/Malachi-tithing.html