How much is a ticket from London to Frankfurt?

The cheapest price found today is $21.

When is it cheaper to fly?

Cheapest month is September — from $21.

Cheapest today — $21. Below is what booking services offer.

Departure	Airline	Stops	Price
Sep 21	Malta Air	direct	$21	View
Sep 15	Malta Air	direct	$21	View
Sep 2	Ryanair	direct	$22	View
Sep 4	Malta Air	direct	$22	View
Sep 9	Ryanair	direct	$22	View
Sep 18	Ryanair	direct	$22	View
Sep 25	Ryanair	direct	$22	View
Sep 24	Ryanair	direct	$22	View
Sep 30	Malta Air	direct	$22	View
Sep 26	Ryanair	direct	$23	View

How much is a ticket from London to Frankfurt?: The cheapest price found today is $21.
When is it cheaper to fly?: Cheapest month is September — from $21.

Links to booking services are affiliate links. The price stays the same for you.