Dildo Sizes: Buy What Feels Good, Not What Looks Huge

The dildo looked perfectly reasonable on your phone. Then the parcel arrived and you realised the photo had been doing a shitload of favours for your sense of scale.

A few measurements before you buy can prevent that particular surprise. Start with width and insertable length, then consider shape and firmness. “Large” means very little without numbers beside it, and a flattering camera angle tells you bugger-all.

Width and girth are different measurements

Diameter measures straight across a round dildo. Girth, also called circumference, measures around it. Mix those up and you can order something very different from what you pictured.

For a round shaft, circumference is roughly diameter multiplied by 3.14. A diameter of 3 cm means about 9.4 cm around. Those are two ways of describing the same width, not two sizes to choose between.

Oval or irregular shapes need more care because one diameter won't describe the whole shape. Include the widest part you'll actually be inserting, including a larger head or raised bumps. Your body won't politely ignore those because the rest of the shaft looked manageable.

Insertable length tells you more than total length

A dildo's total length includes its base or handle. Insertable length is the portion intended to go inside. A chunky suction cup might make the whole toy look long without adding any depth during use.

You don't have to use every centimetre of insertable length, but buying loads of extra length still changes how the toy handles. There's more to hold, position and keep under control. “I'll just be careful” isn't a particularly helpful shopping plan if you already know you prefer something shorter.

Compare insertable length with insertable length. Keep the units the same, too: 1 inch is 2.54 cm. Do the conversion while you're shopping, before you're naked and annoyed with yourself.

Measure the dildo you already enjoy

Your favourite dildo is a better reference than a stranger announcing their preferred size in a review. Find its widest insertable point and the length you comfortably use. Then decide what, if anything, you actually want to change.

Perhaps the width is spot-on but you'd prefer a shorter toy that's easier to hold. Perhaps you like the length and want a little more fullness. Changing one measurement at a time makes the choice much easier to understand.

You can lay a ruler beside the toy and use a soft tape around the shaft. No soft tape? Wrap a strip of paper around it, mark where the ends meet and measure the strip flat. You're measuring the toy on the table, not improvising a bedroom challenge.

Firmness and shape change the feel

Two dildos can have matching measurements and still feel quite different. A rigid glass toy won't bend or squash like a soft silicone one. A pronounced curve puts pressure somewhere a straight shaft might not.

Our silicone versus glass comparison explains that difference. If you're adding ribs, bumps or veins as well, the textured versus smooth dildo guide helps separate the choices.

Don't accidentally buy more width, extra firmness and a load of texture when all you wanted was a different colour. Horny shopping is still shopping. You can get carried away by the purple one.

Your first dildo doesn't need to impress anyone

If you have no toy to compare with, choose a modest size that sounds comfortable to try. There isn't one beginner measurement that suits every body, and buying the biggest cock in the collection won't make you better at using it.

Use plenty of suitable lube, take your time and stop if it hurts. For anal use, choose a toy made for it with a wide flared base that stays outside; our flared-base guide explains why.

Browse our dildos with the size you want in mind. Small, medium and large are useful shelf labels, not a ladder you're supposed to climb. A dildo that feels bloody good doesn't need replacing just because a bigger one exists.