Tarp size for solo and duo?

I think most will recommend 8 x 10 if there might be two. If windy and wet then I’d consider adding water resistent bivies or oversized tyvek groundsheet

In my opinion, anything smaller than an 8×10 for a solo hiker is not suitable for bad weather. An 8×10 works just fine for 2 people as well. It’s mostly dealing with wind blow rain coming it at the ends of the tarp, which is why you want it 10 feet long. The sides will be pinned down anyways.

So to answer your question I think an 8×10 works equally well for one person or two people and anything smaller is foolish if you are expecting bad weather. Maybe 10 feet wide would be better for two people, but more weight. Expect to carry about 14 ounces, tarps aren’t really that much lighter than a pyramid shelter unless you don’t use trekking poles and need to carry a dedicated pole.

What about 8.5’x8.5′, which pitched on a low diagonal is 12′ long? Or 8’x9′ / 8’x9.5′ with one end low and the other sealed off with an umbrella or my partner’s rain skirt? She is only 5’4″ and I’m hardly a giant at 5’7″.

I like my Gossamer Gear C-Twinn as it is more affordable than Cuben and light enough for solo use. I have to admit the catenary cut steals a lot of headroom, though, but that’s inherent with nearly all cat-cut tarps (and can be mitigated by a higher setup).

Theo – yes, the GG tarps look great, as do a number of cat cut tarps (MLD Grace in particular), but I’m really looking for the flexibility of a flat tarp. In the wind and rain I’d really want a storm pitch, and I really like a half pyramid in milder conditions. But yours is certainly nice and light for a non-cuben tarp.

I have an 8.5′ x 8.5′ flat tarp, but if I were to do it over, I might go with 8′ x 10′ instead.

I’ve used it solo in the Southeast US in all sorts of weather (except late spring and summer, where I like the bug protection of a tent), including wind and rain. Careful site selection, pitching one end close to the ground, and using rain gear to close up the open end make it work, but a little more length would be handy.

My two dogs, my son (11 years old at the time), and I even managed to spent one very rainy night under it, pitched in an A frame (maybe not the best choice). We stayed dry, but the feet of our sleeping bags did get wet. Again, it worked, but the extra length would have been helpful.

Lastly, my girlfriend and I (both short, 5’2″ and 5’6″) have used it for several nights in the Rockies (late summer, little rain). In this environment, it was just about perfect. I had no complaints about the size, but an 8 x 10 tarp weighs only slightly more, so it would also have worked very well.

Long story short: I think you could make an 8.5 x 8.5 tarp work, but 8 x 10 is probably better when you expect rain.