I know, I know. When you’re sitting in bumper-to-bumper traffic near the Dartford Crossing, it feels more like 1,170 miles. But nope, the concrete serpent is exactly 117 miles around. For context, that’s roughly the distance from London to Birmingham. The M25 is so long that it actually passes through five counties: Kent, Surrey, Buckinghamshire, Hertfordshire, and Essex. It’s like a road trip that never leaves the ‘burbs.
Fun fact: If you drove the M25 at exactly 70 mph with no traffic (laughable, I know), you’d complete the loop in about 1 hour and 40 minutes. In real life, you’ll need to pack snacks, a podcast, and possibly your will to live.
But Wait—Is the M25 Actually a Full Circle?
Here’s where it gets weird. The M25 isn’t a perfect circle—it’s more of a wonky oval that looks like a circle on a map until you realize it’s missing a bit. The original plan was to build a complete ring, but costs and protests left a gap. Today, the official route uses the A282 for the Dartford Crossing, which is basically the M25’s awkward cousin. So technically, the full loop with the A282 is 117 miles. Without it? You’d have to swim across the Thames.
Think of it this way: the M25 is like a donut with a bite taken out, and that bite is the Dartford Tunnel. Deep, right?
