Short answer: No cap fits literally everyone, so treat "one size fits all" as a claim to check against a head measurement. A one-size ponytail cap can work well if the maker states a circumference range and gives you a way to adjust. Ponyloop (we make it, so read this with that in mind) sells caps in one size for 54 to 62 cm, with a foam insert for smaller heads.
Can one size really fit everyone?
Not in the literal sense. Head sizes vary, and a cap that is comfortable at one end of its range may be loose or tight at the other. A useful one-size cap tells you the range in centimetres. If a listing only says "fits all" with no number, you cannot verify it.
How do I measure my head for a ponytail cap?
- Take a soft measuring tape.
- Wrap it around your head about 1 cm above the ears.
- Keep it level at the front and back, snug but not tight.
- Compare the number in centimetres with the range stated by the brand.
If you are close to the edge of a range, pick the option that offers an adjustment or a sizing aid.
What size range does Ponyloop cover?
Ponyloop caps come in one size for a head circumference of 54 to 62 cm. A black foam insert (sizing clip) is included. It makes the cap about 2 to 3 cm smaller and is intended for a head circumference under 56 cm. If you are 56 cm or more, you do not need it. The caps are made of a stretch material, described as recycled polyester, lightweight and breathable.
Ponyloop caps are designed for women. The beanies are also one size and stretchy.
Which Ponyloop cap should I look at?
- PonyLoop Original: magnetic closure on the back, 4 colors (Black, Gray, Navy, White), 24.99 EUR.
- PonyLoop Vintage: trucker cap with a washed look, mesh, crossed elastic bands (CrissCross) that your hair goes through, 6 colors, 24.99 EUR.
- PonyLoop Glitter: glitter finish, CrissCross design, several colors, 24.99 EUR.
The magnetic closure and the crossed elastic bands are two different ways to let a ponytail, bun or braid pass through the back. The right choice is mostly a matter of how you wear your hair.
What are the alternatives if one size does not suit me?
Some brands sell several fixed sizes instead of one adjustable size. According to our comparison article (brand sites checked on 10 October 2026), Ponyback, a Canadian brand, offers 7 sizes from 50 to 62 cm, priced in Canadian dollars. Ponyflo, a US brand, ships in the U.S. only according to its shipping policy. See the full comparison, including our disclosure that we make one of the three: Ponyloop vs Ponyflo vs Ponyback.
If your head is outside 54 to 62 cm, a multi-size brand may be the safer choice. Measure first and decide with the number in hand.
What if the cap does not fit when it arrives?
Ponyloop offers a voluntary one-time exchange. You can request it within 14 days if the size or color does not suit you. The item must only have been tried on, not worn or washed, in original condition with tags and packaging. You pay the return shipping, Ponyloop pays shipping of the exchanged item, and there is no refund of the purchase price. Details are on the Returns & Exchanges page.
Where can I buy in Europe, and how long does delivery take?
Customers in Germany order at de.ponyloop.com in German. The English store at eu.ponyloop.com serves 31 other European countries, including Austria, Switzerland, France, the Netherlands and the UK. Delivery usually takes 1 to 3 weeks after payment, and in rare cases up to 40 days. There is no express option. Shipping costs are shown at checkout.
Quick checklist before you buy any one-size cap
- Is a range in centimetres stated?
- Is there an insert, strap or stretch to adjust the fit?
- Is the opening type clear (magnetic, elastic bands, Velcro)?
- Is the exchange policy clear, and who pays return shipping?
- Does the brand ship to your country?
Frequently asked questions
What head size does a Ponyloop cap fit?
One size for a head circumference of 54 to 62 cm. Measure about 1 cm above your ears.
What is the foam insert for?
The included black foam insert makes the cap about 2 to 3 cm smaller. It is intended for a head circumference under 56 cm.
Does a one-size cap fit every head?
No. Check the stated range against your measurement. If you are outside it, consider a brand with several fixed sizes.
Can I exchange a Ponyloop cap if the size is wrong?
Yes, there is a voluntary one-time exchange within 14 days under the conditions on the Returns & Exchanges page. There is no refund.
How long does delivery take?
Usually 1 to 3 weeks after payment, and up to 40 days in rare cases. There is no express option.