Excel Challenge 5 : Extract Email Domains

What You Will Learn

Five email addresses like "tony@stark.com" and "peter.p@dailybugle.net". You need to extract just the domain part — everything after the @ sign — into column B.

The @ sign is the fixed marker. Every email has one, and the domain always comes after it. FIND locates the @, then MID returns everything from that point to the end:

=MID(A2, FIND("@", A2) + 1, LEN(A2))

Breaking it down:

FIND("@", A2) — returns the position of the @ sign. For "tony@stark.com" it returns 5.
+ 1 — moves past the @ so the result starts with "s" instead of "@".
MID(A2, ..., LEN(A2)) — starts at that position and returns the rest of the string. LEN(A2) just means "give me everything remaining".

For "tony@stark.com": FIND returns 5, MID starts at 6, and returns "stark.com". Same logic works for every email regardless of username length.

FIND locates the @, MID returns everything after it.

The audit formulas:

B9: =COUNTA(A2:A6) — counts total emails.
B10: =COUNTUNIQUE(B2:B6) — counts how many unique domains appear. This checks the extracted domain column, not the original emails.

In this list, all five domains are different (stark.com, dailybugle.net, wayne.co, dailyplanet.com, themyscira.gov), so the unique count is 5.

Alternative Approaches

RIGHT + LEN: Calculate how many characters are after the @, then use RIGHT:

=RIGHT(A2, LEN(A2) - FIND("@", A2))

REPLACE: Delete everything up to and including the @:

=REPLACE(A2, 1, FIND("@", A2), "")

All three return the same result. The MID version is the most commonly used because it reads clearly: "start after the @ and take the rest."

The LEN(A2) at the end of the MID formula acts as a "give me everything until the end" signal. It does not matter how long the domain is — 8 characters or 80 — MID keeps going until it runs out of text. That is what makes this pattern work for any email length without adjustment.

This pattern works only when every address has a single @ sign. If the data contains malformed emails (missing @, multiple @), the formula may return unexpected results. For clean lists like this one, it is reliable.