Your cell phone. Jokes aside, anything that can run this website will be more than sufficient to run Classic, unless you haven't upgraded your PC in the past 15 years. I'm not sure on the specs, but I'm sure you will be fine.

One of the r/classicwow mods just posted a huge thread on this: https://www.reddit.com/r/classicwow/comments/c23tlc/i_spent_600_buying_old_pc_parts_to_benchmark_the/

Looks like pretty much anything can run it on low graphics.

SoupaSouka did a great job on that thread even buying up old PC rigs for benchmarking.

One of the r/classicwow mods just posted a huge thread on this: https://www.reddit.com/r/classicwow/comments/c23tlc/i_spent_600_buying_old_pc_parts_to_benchmark_the/

Looks like pretty much anything can run it on low graphics.

This absolute hero spent over $600 to benchmark Classic on old machines.

I upgraded my Commodore 64 the the C128, you think I'll be OK?

Just finished playing on the latest stress test. Had an amazing experience. Here's my (work) laptop specs:

2.5 GHz Intel Core i7
16 GB 2133 MHz LPDDR3
Intel Iris Plus Graphics 640 1536 MB

I was mildly considering building a PC (haven't owned one since like 2005) for Classic but all I needed was a mouse.