29.2 miles of 477
That's how far the needle on my record player has physically traveled, tracing the groove, listening to my way through this collection — not how far the tonearm swings side to side (an inch or two), but the actual length of the spiral path the stylus rides, unspooled into a straight line.
How this is calculated
A record's groove is a spiral, but the spiral's pitch — the tiny gap between adjacent turns, a few thousandths of an inch — is negligible next to its radius, which is measured in inches. So the exact arc length of the spiral collapses to something much simpler: treat each individual revolution as a plain circle at that revolution's radius, and add them all up. For a record spinning at a constant speed for some number of minutes, that works out to:
distance = 2π × RPM × minutes played × average groove radius
Average groove radius depends on the format — a 12" LP's groove runs roughly from a 5.75" radius down to 2.35" near the label, so its average is about 4.05". A 7" single's groove occupies a much smaller band, so it contributes far less distance per minute despite spinning faster (45 RPM vs. 33⅓).
Where the numbers come from
Format and speed come from the same catalog data Discogs already has for each release in the collection. Minutes played is the harder part — it needs a real runtime for every record, not just a track count. 471 of 739 records' timings come straight from Discogs' own tracklist data; 163 more come from Wikipedia's infobox runtime, for anything Discogs didn't have complete track times for; the remaining 105 get a flat per-format estimate. That default is a rough per-format average (roughly 19 minutes per side for a 12" LP, less for smaller/faster formats) — a small enough slice of the total that it doesn't move the number much either way.
Caveats, for the honest version of this
This assumes standard groove geometry for every format, when real mastering varies — a quiet, sparse album can be cut with a wider groove pitch and end further from the label than a loud, dense one, and neither Discogs nor Wikipedia expose that. It's a physically grounded estimate, not a measurement of any specific stylus's actual path. Consider it a fun lower-resolution truth rather than a load-bearing one.