For anal beginners, a good rule of thumb is to start with a 1″-1.25″ diameter plug. But if you want a more exact idea of what size you should begin with, play with your fingers. Lube them up, see how many you can fit in your butt, then measure their circumference. Divide your measurement by pi and choose a plug with a diameter as close to this as possible.
Get a plug with a t-bar base, not a round base. A t-bar base will fit snugly between your cheeks, so you can walk around and it won’t chafe you. The only downside of a t-bar base is it may occlude the vagina. So if you have a vag and you want to fill both holes simultaneously, a round base may be better for you.
If and when you want to size up, I recommend an increment of up to 1″ in circumference, or 0.25″-0.3″ in diameter. This should give you a challenging, yet fun and doable stretch.
If you attempt an increment much bigger than this, either it won’t go in or you’ll hurt yourself. If you try a smaller increment, you may find it too easy and too similar to your previous toy.
Don’t forget lube: Too much is barely enough. I recommend coconut oil because it lasts longer than water-based lube and, unlike silicone-based lube, it won’t damage silicone toys. But remember oil eats latex, so don’t use it with condoms. If you’d prefer water-based lube, I love Sliquid’s Sassy.
Here are some well-designed, inexpensive starter plugs:
- Doc Johnson’s Mood Naughty in medium (1″ diameter) or large (1.25″ diameter). The small is so small you don’t need to bother with it. Its 0.75″ diameter is thinner than a thumb. You can also get all three in a set for a discount.
- CalExotics’ Silicone Anal Exerciser Kit. It comes with 1″, 1.25″, and 1.5″ diameter plugs.
- Pipedream’s Anal Fantasy Collection Mini Silicone Plug (1″ diameter). It’s a good plug, but be aware it comes with a small tube of Anal Eaze. Throw that shit out. Desensitizing your ass is a bad idea. You need to be able to feel pain. That’s how you know when something’s wrong.
- Titus’ Silicone Series Butt Plugs in small (~1.1″ diameter) or medium (~1.25″ diameter). You can also get them in a set that comes with a ~1.6″ diameter large size.
- Fuze’s Pleasure Plug 2 (1.25″ diameter). The Pleasure Plug 1 only has a 0.875″ diameter, so you can skip it over.
- Vedo’s Bump (1.17″ diameter), which I reviewed here. I normally don’t recommend vibrating beginner plugs because they cost more and many people don’t take long to progress past this size. But the Bump is still fairly inexpensive. And after you outgrow it, you can still use it as a damn good bullet vibrator.
Notice I haven’t mentioned any prostate plugs? That’s because they have bulbous heads, so they’re difficult for beginners to insert. After you’ve gained some experience, check out Aneros, Nexus, Lovense’s Edge, Tantus’ Prostate Play, and Doc Johnson’s Mood Naughty 2.