Short answer
Zakat (Arabic زكاة) means purification and growth. In Islamic law it is the fixed share of wealth, 2.5 percent on savings, that a Muslim who owns the nisab for a lunar year must give to eligible people. It is the third pillar of Islam and fard in all four schools.
Zakat is fard (obligatory). The Hanafi jurists define it as handing over a share of wealth set by the Sharia into the ownership of an eligible poor Muslim, for Allah alone, with no benefit coming back to the giver. Denying that it is a duty takes a person out of Islam; holding back while believing in it is a major sin.
The four schools agree on this.
Explanation
The Arabic word zakat comes from a root that means both to grow and to be pure. You will see it spelled zakat, zakah or zakaat. They are the same word: the last letter is pronounced as a soft h when you stop on it. In English it is often translated as alms, obligatory charity or purifying alms.
Both meanings fit what zakat does. The Quran tells the Prophet ﷺ to take charity from the believers' wealth to purify them and cause them increase (9:103). Giving cleans the heart of greed and the wealth of the right of the poor that sits inside it, and Allah puts blessing in what remains.
In Islamic law the word has a precise meaning. In brief:
- Who pays: an adult, sane Muslim who owns the nisab beyond debts and basic needs for a lunar year (see who has to pay zakat).
- On what: cash, gold, silver, trade goods, grazing livestock and crops (see what zakat is due on).
- How much: 2.5 percent for money (see how much is zakat).
- To whom: the eight groups in Quran 9:60, mainly poor and needy Muslims (see who can receive zakat).
Zakat is the third of the five pillars of Islam, named after the testimony of faith and prayer. The four schools agree on its obligation and on its basic rules. Two related words cause confusion: zakat al-fitr is a separate small payment made for each person before Eid al-Fitr, and sadaqah is voluntary charity of any amount (see zakat vs sadaqah). Our zakat calculator works out what you owe.
The evidence
Quran, Surah At-Tawba 9:103
خُذْ مِنْ أَمْوَٰلِهِمْ صَدَقَةًۭ تُطَهِّرُهُمْ وَتُزَكِّيهِم بِهَا وَصَلِّ عَلَيْهِمْ ۖ إِنَّ صَلَوٰتَكَ سَكَنٌۭ لَّهُمْ ۗ وَٱللَّهُ سَمِيعٌ عَلِيمٌ ﴿١٠٣﴾
Take, [O, Muhammad], from their wealth a charity by which you purify them and cause them increase, and invoke [Allah 's blessings] upon them. Indeed, your invocations are reassurance for them. And Allah is Hearing and Knowing.
The verse names both meanings of zakat: purification and growth.
Quran, Surah Al-Baqara 2:43
وَأَقِيمُوا۟ ٱلصَّلَوٰةَ وَءَاتُوا۟ ٱلزَّكَوٰةَ وَٱرْكَعُوا۟ مَعَ ٱلرَّٰكِعِينَ ﴿٤٣﴾
And establish prayer and give zakah and bow with those who bow [in worship and obedience].
Zakat is commanded together with prayer as a duty of every believer.
Sahih al-Bukhari 8
Sahih... وإقام الصلاة وإيتاء الزكاة والحج وصوم رمضان ...
"Islam is built on five: the testimony of faith, establishing prayer, giving zakat, Hajj and fasting Ramadan."
Zakat is one of the five pillars on which Islam is built.
Where the ruling is recorded
- al-Durr al-Mukhtar with Radd al-Muhtar, Kitab al-Zakat, opening definition. Defines zakat as making a poor Muslim the owner of a set part of wealth, for Allah, with no benefit returning to the giver.
- al-Hidaya, Kitab al-Zakat, opening section. Zakat is obligatory on a free, adult, sane Muslim who fully owns a nisab for a year.
Checked by our team. For a more accurate answer to your own situation, consult a scholar. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.